* Manchester City scoring machine roars on
* Arsenal's lead cut to two points in title race
* Chelsea struggle to beat lowly Palace 2-1
* Everton overcome Fulham to move into top four (Adds details)
By Toby Davis
LONDON, Dec 14 (Reuters) - Manchester City exposed the first cracks in Arsenal's title challenge, beating the Premier League leaders 6-3 at the Etihad Stadium as their attacking talents cut loose in another free-scoring home display on Saturday.
City's stylish showmen sealed their eighth consecutive home league success in an exhilarating match by outgunning Arsenal, whose advantage at the top was cut to two points after Chelsea sneaked a 2-1 win at home to Crystal Palace.
Everton's 4-1 win over visitors Fulham moved them into the Champions League spots as they jumped to fourth, while at the other end of the table West Ham United played out a 0-0 draw with bottom side Sunderland that was little use to either team.
Cardiff City beat West Bromwich Albion 1-0, while Newcastle United and Southampton drew 1-1.
Arsenal's previously watertight defence was prised open at will by the Manchester City's marauding attack.
It was the third time this season that City had scored six goals or more, after they dished out similarly crushing blows to Tottenham Hotspur and Norwich City, and the win moved them up to third place within three points of top spot.
The victory also put down a light blue marker in a now-congested title race that could have turned decisively in Arsenal's favour had the visitors managed to conjure a win.
"At times the tempo was frightening," City captain Vincent Kompany told BT Sport. "We looked to be in control of the game for most of it. There were no standout individual performances but collectively we've done incredibly well.
"It is a real fortress here."
City, whose early opener from Sergio Aguero was cancelled out by Theo Walcott, opened up a two-goal lead with Alvaro Negredo and Fernandinho efforts either side of halftime.
Arsenal rallied with a superb second by Walcott, who curled the ball into the top corner, but David Silva restored City's two-goal advantage from close range and Fernandinho poked home his second as City kept up their 100 percent home league record.
Even defender Per Mertesacker's late consolation for Arsenal was trumped by City as Yaya Toure stroked in a stoppage time penalty.
The final whistle prompted a scuffle between Mertesacker and Mesut Ozil, with the centre back seemingly angered by his Germany team mate's reluctance to applaud the visiting fans.
Arsenal's failure to pull clear at the top was a fillip for Chelsea but struggling Crystal Palace proved trickier opponents than expected and manager Jose Mourinho ended the match grateful to Petr Cech for helping them over the finish line.
The Chelsea keeper made a string of fine saves to keep the visitors at bay after midfielder Ramires put the home side back in front with a curler 10 minutes before halftime.
Fernando Torres had given Chelsea the lead after 16 minutes with a tap-in, but Palace striker Marouane Chamakh scored for the third consecutive league game with a volley to equalise.
"To be top... by December or even by the end of January I don't think is crucial," Mourinho told reporters. "I think this will be open till very very late. It's a very hard league."
Everton, who won plaudits for their performance in a 1-1 draw at Arsenal last weekend, showed they are serious contenders for a top-four finish with a battling home win over Fulham.
After a dominant first-half display in which Leon Osman curled in the opener for Everton, the hosts were pegged back by Dimitar Berbatov's penalty after 67 minutes.
Goals from Seamus Coleman, Gareth Barry and Kevin Mirallas in the final 17 minutes gave the scoreline a more satisfying gloss for Roberto Martinez's in-form side.
Newcastle and Southampton shared the spoils at St James' Park with Jay Rodriguez equalising for the visitors in the 65th after the Magpies had gone ahead through Yoann Gouffran just befor the half-hour mark.
The game, however, ended in a feisty exchange between the two benches and referee Mike Jones was accidentally floored by Newcastle's Moussa Sissoko, who caught the official in the face after gesturing to a Southampton player to get up.
Newcastle moved up to sixth with 27 points, three clear of Southampton in eighth.
West Ham blew the chance to move clear of the relegation zone after a goalless stalemate at home to Sunderland, leaving manager Sam Allardyce to bemoan their lack of scoring options.
With England striker Andy Carroll still out and no return date yet pencilled in, the Hammers have scored once in their last three and are one point above the relegation zone.
"We have got eight clean sheets so far this season. That is a brilliant return as we only got 11 last season," said Allardyce. "We all know the goal factor is the problem for us and we would be higher up the league if we could score more."
Mid-table Hull City and Stoke City meet later on Saturday while fifth-placed Liverpool can move back into second spot if they beat seventh-placed Tottenham Hotspur away on Sunday. (Reporting by Toby Davis; editing by Martyn Herman and Ken Ferris)