Didier Drogba scored twice Saturday as Chelsea won 2-0 at Wolves to open a four-point lead in the Premier League after Manchester United had lost 3-1 at Everton.
Arsenal moved closer to Man United with a 2-0 victory over Sunderland but remains six points behind Chelsea.
Drogba hit the target in the 40th and 67th minutes at Molineux to take his tally for the season to 25 in all competitions and lift Chelsea to 61 points. United has 57 points, two more than the Gunners.
Everton substitutes Dan Gosling and Jack Rodwell scored late goals to come from behind to beat United at Goodison Park.
After Dimitar Berbatov had given United a 16th-minute lead, Everton equalized through Diniyar Bilyaletdinov three minutes later.
Gosling fired the home side ahead in the 76th, and Rodwell went on a weaving run to hit the third in the 90th after having only been on the field for three minutes.
"It's a bad result for us at this time of the year," United manager Alex Ferguson said. "We can't afford a result that we had today. We hope that others will drop points.
"We looked really tired today and we were well beaten, simple as that."
Everton manager David Moyes saluted his substitutes but also his entire team, which was missing midfielders Tim Cahill and Marouane Fellaini through injury.
"The substitutes came in today and made an impact in the game," said Moyes, whose side is chasing a place in Europe next season after a long spell in the bottom half of the standings. "We can start looking up now rather than down."
Niklas Bendtner gave Arsenal a 27th-minute lead at Emirates Stadium from Emmanuel Eboue's cross but Arsene Wenger's team had to wait until a last-minute penalty to make sure of the points. Cesc Fabregas was brought down by Fraizer Campbell and he got up to stroke home the spot kick for his 15th goal of the season.
West Ham's revival continued with a 3-0 victory over Hull to put the visitors deeper in trouble.
Valon Behrami's first goal of the season in the second minute put the Hammers on course for victory. Carlton Cole added a second in the 59th and Julien Faubert a third near the end.
While Gianfranco Zola's West Ham moved closer to safety, Hull remained a point above the relegation zone but has played two more games than the three teams below.
Last-place Portsmouth is at home to Stoke in Saturday's late match.
On Sunday, Aston Villa meets Burnley, Bolton goes to Blackburn, Fulham welcomes Birmingham, Manchester City hosts Liverpool and Tottenham visits Wigan.Reuse content