(Adds late game)
By Toby Davis
LONDON, March 8 (Reuters) - Chelsea surged seven points clear at the top of the Premier League after a 4-0 demolition of London rivals Tottenham Hotspur on Saturday.
A trademark poacher's goal from Samuel Eto'o, a penalty from Chelsea top scorer Eden Hazard and two strikes in the last three minutes by Demba Ba did the damage as Tottenham, reduced to 10 men for most of the second half, imploded.
Chelsea's main title rivals, Arsenal and Manchester City, were in Cup action this weekend and have games in hand over Jose Mourinho's side.
But champions Manchester United rediscovered a touch of their old swagger, easing past struggling West Bromwich Albion 3-0 to record back-to-back Premier League wins for the first time since December.
Phil Jones headed home a Robin van Persie free kick in the first half, Wayne Rooney finished a sweeping passing move with a header after the break and Danny Welbeck added a third to inflict further misery on a woeful West Brom side.
Fifth-placed Spurs played the last half-hour with 10 men after French defender Younes Kaboul was sent off for bringing Eto'o down in the penalty area and they made costly defensive mistakes.
The Cameroon striker, a late addition to the starting lineup after Fernando Torres limped off in the warm-up, put Chelsea ahead in the 56th minute.
Tottenham defender Jan Vertonghen slipped and attempted to clear the ball from the ground but only pushed it into Eto'o's path.
It was the 300th goal of Eto'o's career and he celebrated by bending over the corner flag like an old man, a nod to recent controversy about his age.
Three minutes later Hazard converted a penalty after Younes Kaboul brought down Eto'o in the area. Referee Michael Oliver sent the French defender off and what had been a balanced game between two committed sides quickly became a rout.
Chelsea's Senegalese substitute Ba put away an Oscar pass for his first goal and latched on to an reckless headed back pass from Kyle Walker for the second.
West Brom and manager Pepe Mel, winless since taking over in early January, stayed one place above the relegation zone but level on points with Cardiff City who beat bottom club Fulham 3-1 with two goals from Steven Caulker.
Hovering above them are Crystal Palace, who missed the opportunity to pull five points clear of trouble after a 1-0 defeat by Southampton, while Norwich City, in 15th, were held to a 1-1 draw by Stoke City.
United, whose last outing was a demoralising Champions League defeat by Olympiakos, moved up to sixth in the table on 48 points, bringing rare cheer to manager David Moyes.
"It was more like it," the United boss told the BBC.
"We were more creative and played well. It's never the easiest of places to come and we had lost to them earlier in the season so it was good to get a good result."
Moyes shuffled his pack after the poor showing in Europe, adding a youthful complexion to his defence where Jones was paired with Chris Smalling.
For most of the first half the pair looked unconvincing as United struggled to find any rhythm or tempo, but at the other end of the pitch Jones made a decisive contribution.
After Rafael had forced United's former keeper Ben Foster to tip his header on to the bar, Jones opened the scoring by powerfully heading home a Van Persie set piece after 34 minutes.
The second half began with controversy as Van Persie escaped a second yellow card when he slid into a reckless challenge, only to receive a final warning from the referee.
The more the hosts pushed forward, however, the more they looked vulnerable and Rooney effectively sealed the points in the 65th minute, heading in a cross from Rafael after a sweeping passing move from Moyes's side.
United's talented forward players, neutered for most of this season, began to strut their stuff and Welbeck finished off an intricate passing move with an angled shot beyond Foster to complete the scoring.
Cardiff had won only one of their last 12 Premier League games and failed to score in their last four but ended that run when Caulker put them ahead with a close-range finish just before the break.
Fulham drew level through Lewis Holtby but Caulker restored the hosts' advantage with a far-post header and an own goal from Sascha Riether made the game safe to leave Fulham four points adrift of safety.
Southampton had lost three successive games in the league and Cup but edged a tight clash against Palace thanks to a first-half goal from Jay Rodriguez.
The England forward chased down a poor Jason Puncheon header to challenge Palace keeper Julian Speroni and hit the ball into an empty net.
It was a mixed afternoon for Stoke's Jonathan Walters who netted from the penalty spot to equalise Bradley Johnson's opener for Norwich before the striker was sent off for a high challenge on Alexander Tettey. (Additioanl reporting by Clare Lovell; Editing by Ed Osmond)