Leicester Tigers held on to record their second win of the Premiership campaign in a frenetic game against Harlequins that featured three tries and a yellow card for either side.
Tigers full-back Telusa Veainu lit up the first half, burrowing over from close range to score the opening try before torturing the hosts with his dazzling counter-attacking.
In a match that was billed as a head-to-head clash between two fly-halves - Marcus Smith and established international George Ford - Harlequins' teenage number 10 landed three first-half penalties and directed play well.
Although Leicester went into half-time 11-9 ahead, two tries in three minutes soon after the break from Danny Care and Mat Luamanu put Harlequins 21-11 in front.
Scrums were messy throughout, and referee Ian Tempest sent both Leicester loosehead Ellis Genge and Harlequins tighthead Will Collier to the sin bin simultaneously. Marcus Smith was also forced to withdraw due to injury, which stunted Harlequins' attack.
The open spaces suited Leicester, who replied through Jonny May, latching onto Matt Toomua's pass, and replacement prop Greg Bateman, set free by Ford.
Alofa Alofa's try put Harlequins back in front, but two penalties from Ford sealed the result for Tigers following a stretched finale.
Full-time! Harlequins 28-31 Leicester Tigers
Crazy until the end. Harlequins eke out a ruck penalty. Danny Care taps and goes before Mike Brown aims a kick across the field. Leicester just about recover it and get a penalty of their own. That finishes a remarkable game.
Harlequins 28-31 Leicester Tigers, 79 minutes
Harlequins are probing and going through the phases within their own 22. They're being patient. They have the attacking quality to work an opening and Leicester look shattered...
Harlequins 28-31 Leicester Tigers, 77 minutes
We need about three re-sets at a midfield scrum before Leicester come away and break left. Jonny May and Sam Harrison break through the fringes and bring Tigers to within five metres...but then Dom Barrow spills under pressure!
Mike Brown still on
Physio now chasing him but Brown unrelenting in wanting to stay on. https://t.co/XWIa5RIoR1
— Nick Heath (@nickheathsport) September 23, 2017
Penalty, George Ford! Harlequins 28-31 Leicester Tigers, 73 minutes
After all that, Ford puts Leicester ahead.
Harlequins 28-28 Leicester Tigers, 69 minutes
Carnage. CARNAGE. Harlequins win a breakdown turnover and that is only the beginning of the chaos. Mathew Tait storms through to make a huge tackle but Harlequins work the ball to Yarde, who chips over the top and seems to be hit by Veainu.
George Ford then kicks downfield, Nick Malouf runs through to collect and Harlequins infringe at the breakdown. That could have been a yellow card.
Meanwhile, Mike Brown is limping badly.
Matt Smith replaces Mat Tait for a HIA, but is not fit enough for Joe Ford will be on instead.
Harlequins 28-28 Leicester Tigers, 69 minutes
This game is there for someone to grab. Danny Care bounces a kick into touch and Leicester loose the lineout. Harlequins cycle through the phases and get to the 22 but cough it up...
...then there is a huge Leicester shove that wins a scrum penalty.
Penalty, George Ford! Harlequins 28-28 Leicester Tigers, 66 minutes
Matt Toomua carries hard off the scrum. Jamie Roberts makes the tackle but cannot roll away. Ford levels it up. Harry Thacker is back off for Leicester, as is Dan Cole. Tom Youngs comes back on and Logo Mulipola joins the game as well.
Harlequins 28-25 Leicester Tigers, 64 minutes
Harlequins spill the restart and it's a Leicester scrum. Sinckler and Genge are enjoying themselves here. There could be a flashpoint coming...
Jack Clifford has been excellent again.
Try, Alofa Alofa! Harlequins 28-25 Leicester Tigers, 62 minutes
Excellent play from Danny Care, who orchestrated that attack. He spins to the blindside and plays a lovely pass to Alofa, who surges through.
Harlequins 21-25 Leicester Tigers, 60 minutes
Genge and Collier are back with us. Well, Collier isn't because Kyle Sinckler is staying on. Harlequins win e penalty and are into the Leicester 22...now they're within five metres with penalty advantage...
Ben Coles at the ground...
"Matt Toomua's feeling it. The mini pump and then wide ball for Jonny May's try was a beauty, and he's just followed it up with a booming clearance kick. Leicester right on top now."
Try, Greg Bateman! Harlequins 21-25 Leicester Tigers, 57 minutes
What a game this is. Leicester are thriving in the open expanses with George Ford pulling the strings very nicely. The fly-half goes to the line and sends Bateman scurrying through. Mike Brown cannot bring him down and, with Ford's conversion, tigers have a four-point lead.
Try, Jonny May! Harlequins 21-18 Leicester Tigers, 54 minutes
It's getting very fractured now. Sinckler knocks on as Harlequins are in phase play and Ben Youngs sparks a lovely counter. Matt Toomua flings a gorgeous flat pass to May to capitalise on an overlap. Classy score.
Yellow cards, Will Collier (Harlequins), Ellis Genge (Leicester Tigers)
Ian Tempest has had enough of the scrum re-sets. He's sin-binned two props.
Kyle Sinckler comes on and wins a penalty immediately. Then has a bit of a swear. He's fired up.
Marcus Simth has also left the field. That looks like a muscular injury to his right leg.
Here are Mike Brown and Harry Wells going at it.
Harlequins 21-11 Leicester Tigers, 47 minutes
Chris Robshaw is coming off. He looked to be knocked out while Leicester were in possession before Luamanu's try.
Try, Mat Luamanu! Harlequins 21-11 Leicester Tigers, 46 minutes
Almost impressively insipid from Leicester. They try to go wide but Veainu cannot hold onto Ford's pass. Smith flicks the loose ball to Yarde, who releases Luamanu. Two tries in two minutes from Leicester Tigers mistakes.
Try, Danny Care! Harlequins 16-11 Leicester Tigers, 45 minutes
Total capitulation from Leicester. Their own scrum splinters, Alofa Alofa speeds down the wing and Ellis Genge is offside as the ball is recycled. Danny Care takes a quick tap and scores a straightforward try.
Harlequins 9-11 Leicester Tigers, 43 minutes
Harlequins are looking very promising. Their attack is brought back for Jamie Roberts' forward pass to the impressive Jack Clifford.
Harlequins 9-11 Leicester Tigers, 41 minutes
Harry Wells cannot roll away from the tackle. Harlequins have an early penalty and Marcus Smith goes to touch.
George Ford restarts the game. Marland Yarde takes and Matt Smith fells him.
...and he's had some traffic to deal with
Six tackles, none missed, for George Ford in that first half.
— Ben Coles (@bencoles_) September 23, 2017
Worry over at Allianz Park
Billy Vunipola has limped off for Saracens...
Maggie Alphonsi's view
Cracking 1st half. Loving the battle of the 10s. Marcus Smith v George Ford. Smith such an exciting player to watch. #HARvLEI
— Maggie Alphonsi MBE (@MaggieAlphonsi) September 23, 2017
Half-time | Harlequins 9-11 Leicester Tigers
Sione Kalamafoni takes the ball from the base and Ben Youngs kicks it out.
Ben Coles at the ground
"Mark Lambert have a torrid time at loosehead for Harlequins, struggling with his bind and keeping the elbow up against Dan Cole. Harlequins creeping up on a double-figure penalty count before half-time."
Harlequins 9-11 Leicester Tigers, 39 minutes
Chris Robshaw is having an excellent game. He harries Ben Youngs into a very rare kicking error. However, Rob Buchanan's throw is not straight. Scrum to Tigers.
Penalty, George Ford! Harlequins 9-11 Leicester Tigers, 38 minutes
Very good game, this.
Harlequins 9-8 Leicester Tigers, 37 minutes
Ellis Genge picks, goes and wins a penalty for Leicester when Rob Buchanan cannot roll away. George Ford will look to take three points and the lead.
Nice shot of Joe Marler and Kyle Sinckler having a chat.
Harlequins 9-8 Leicester Tigers, 35 minutes
Leicester's lineout is stolen by Chris Robshaw but Tigers come again and Ben Youngs bursts through. He grubbers for George Ford to chase but Marcus Smith is back to save the day.
Harlequins 9-8 Leicester Tigers, 32 minutes
Referee Ian Tempest penalises Leicester from the same five-metre scrum! Ellis Genge looks incredulous.
Harlequins are into their expansive shape from the ensuing lineout with Jack Clifford throwing a lovely offload to Jamie Roberts. There is a knock-on, though. Back to a Leicester scrum...and another penalty to the visitors.
Ben Coles at the Twickenham Stoop
"Hard to know what to make of Nick Malouf before the start of the season, one of Leicester's more unknown signings in recent seasons having arrived from Australia Sevens. He looks sharp and strong though in the contact, with Matt O'Connor nearby to where I'm sitting regularly praising Nick 'Magalouf'"
Harlequins 9-8 Leicester Tigers, 30 minutes
Leicester opt for a scrum and eke out two more penalties.
Charlie Walker won't be returning after his head injury assessment, which is a shame. Neither will Dominic Ryan of Leicester.
Harlequins 9-8 Leicester Tigers, 28 minutes
Mike Brown has turned the tetchy gauge up to 11. Leicester are allowed a chance to attack when Marland Yarde spills the restart and Telusa Veainu goes close again, only to be stopped by a high tackle. Penalty Leicester, but not before some handbags initiated by Mr Brown.
Marcus Smith has had to deal with some heavy traffic, but he's distributing very nicely.
Penalty, Marcus Smith! Harlequins 9-8 Leicester Tigers, 26 minutes
Another excellent strike.
Harlequins 6-8 Leicester Tigers, 25 minutes
Dan Cole flies out of the line to smash Marcus Smith but then deliberately knocks on a pass from Danny Care. Marcus Smith will look to put Harlequins in front.
— Oakham Sport (@OakhamSport) September 23, 2017
Harlequins 6-8 Leicester Tigers, 22 minutes
And now 18 year-old Marcus Smith *almost* makes 70-cap Ben Youungs look very silly. Youngs went back to field a bouncing ball and threw a blind pass in-field. Smith stole through and intercepted but was bundled into touch.
Fair to say...
Jonny May owes Telusa Veainu several beers after this #HARvLEI
— Jamie Hosie (@jhosie43) September 23, 2017
Harlequins 6-8 Leicester Tigers, 19 minutes
Wow. That is beauty and the beast from Leiecster. Telusa Veainu utterly shreds Harlequins, beating about five men before streaking into the hosts' half. He links with Jonny May, who throws a shocking pass that Nick Malouf cannot gather. Let off for Harlequins, who have lost Charlie Walker to a head injury assessment.
Ben Coles on Marcus Smith watch at the Twickenham Stoop
Two loop moves in that latest set of phases from Marcus Smith, with Harlequins keen to get the most out of Jamie Roberts as a dummy runner and keep Leicester's wider defence going. The home side are also notably opting for shorter restarts, which Smith has nailed so far.
Penalty, Marcus Smith! Harlequins 6-8 Leicester Tigers, 16 minutes
Ellis Genge gets overeager at a breakdown and Smith has an easy chance to reduce his team's deficit.
Harlequins 3-8 Leicester Tigers, 16 minutes
A rarity. Leicester lose their own scrum ball and Harlequins can press on the edge of the Leicester 22.
Harlequins 3-8 Leicester Tigers, 14 minutes
Robust defence from Tigers sees Marcus Smith crowded out but the visitors concede a penalty as Ben Youngs cannot roll away.
Try, Telusa Veainu! Harlequins 3-8 Leicester Tigers, 10 minutes
The maul was sacked but Leicester react quickly. They go through a few punchy phases before spreading the ball right. Jonny May is off his wing in a second wave to create the extra man and Veainu shunts over from close range.
Ford's conversion misses, but his side have made a strong start.
Harlequins 3-3 Leicester Tigers, 8 minutes
Tigers win the lineout and a strong maul wins a penalty. They're in the corner again...and have another penalty advantage.
Harlequins 3-3 Leicester Tigers, 7 minutes
Leicester work hard to win the restart back and go wide, where Ellis Genge gallops over the gain-line. Leicester recycle robustly off the next phase and win a penalty as Mark Lambert cannot roll away. They go to the corner...
Bright start for Mike Brown
Brown had two excellent games out in Argentina this summer. With every break now, he scans for support. Like Banahan, getting better w/ age.
— Alex Shaw (@alexshawsport) September 23, 2017
Penalty, George Ford! Harlequins 3-3 Leicester Tigers, 5 minutes
Immediate response for the visitors. Harlequins fail to gather the restart cleanly and the Leicester scrum squeezes a penalty out of Will Collier.
Ford bisects the posts from around 30 metres.
Penalty, Marcus Smith! Harlequins 3-0 Leicester Tigers, 3 minutes
Easy start for the teenager.
Harlequins 0-0 Leicester Tigers, 2 minutes
Mat Luamanu finds some space on the left as Harlequins go beyond 10 phases. Smith chips into the corner and the weight of the kick means Jonny May must play it. He throws a hospital pass to Telusa Veainu, who is enveloped and Harlequins win a penalty.
Marcus Smith starts the game, Telusa Veainu collects and Ben Youngs clears. Mike Brown brings it right back.
Leicester skipper Tom Youngs leads out his team. A win brings their season right back on track.
And here come Harlequins, James Horwill at the front of their line.
The conditions - still and mild - are perfect. The surface looks pristine.
Five minutes to go...
— Leicester Tigers (@LeicesterTigers) September 23, 2017
First bit of air-time...
...yep, this guy is going to be on the screen a fair bit this afternoon.
This tweet, from a year ago, is excellent. These two go up against one another in just 10 minutes.
Cheers for the session mate. Hope to see you again soon
— Marcus Smith (@02msmith) May 19, 2016
"The start of the season, the first game, wasn't what we wanted. We're obviously pleased with the last two weeks. Last week's performance [against Wasps] was excellent but it's a fresh start today."
Kingston also says Kyle Sinckler, on the bench today, and Will Collier will be sharing a lot of game-time this season.
Leicester's Australian head coach also highlights the lineout as an area Leicester must improve.
He expects compatriot James Horwill, the Harlequins captain who was immense against Wasps, to come after his side's set piece.
Another Leicester exit
Richard Blaze, Leicester's forwards coach, left the club this week with immediate effect - citing personal reasons as his reason for wanting to move on.
Ben Kay, a BT Sport pundit who also happens to be on the board of directors at Tigers, tells us that there was nothing sinister about Blaze's decision. Brett Deacon takes temporary charge of the Leicester pack.
Ben Youngs' opposite number Danny Care, a long-time England ally, is delighted to be back at the Stoop. Eddie Jones will be watching the match-up at scrum-half very closely, you'd have thought.
As expected, conditions are excellent at the Twickenham Stoop. Ben Youngs says Leicester simply must get their lineout right.
Gloucester lock and Tigers old boy Ed Slater derailed it last week at Welford Road, depriving the hosts of a platform.
Here's a nice preview video from BT Sport.
You'll notice that Harlequins wing Charlie Walker, who has scored in all three games this season, is a prominent protagonist. As a Leicester Tigers Academy product, he'll be eager to impress today.
— Harlequins �� (@Harlequins) September 22, 2017
The fourth round of English domestic fixtures is already underway. Gloucester held on to beat bottom-placed Worcester last night at Kingsholm thanks to two tries from Ollie Thorley.
There are enticing head-to-heads across each of those backlines.
— Leicester Tigers (@LeicesterTigers) September 23, 2017
45 minutes until kick-off
There are other players playing today.
Although their performance was far from polished, Leicester registered their first win of the Premiership campaign seven days ago against Gloucester.
Ben Youngs scored a couple of tries. He reckons his partnership with close mate - and England colleague - George Ford is growing all the time.
Right, let's get this out the way early. Unless you have been living under a rock this week, you will have realised that there has been quite a lot of fuss about Harlequins' 18 year-old fly-half Marcus Smith.
For a comprehensive Smith fact-file, click here.
Hi there and welcome to the first Telegraph live text commentary of the fourth round of Aviva Premiership action.
We'll be tuning into Harlequins' meeting with Leicester Tigers, which promises to be extremely intriguing.
If these shots of Leicester arriving at the Twickenham Stoop are anything to go by, the conditions look fair. We might be in for a fast-paced cracker.