Manchester United returned to the Premier League summit by routing bottom-place Portsmouth 5-0 today, while Manchester City lost 2-1 at relegation-threatened Hull.
Wayne Rooney and Dimitar Berbatov each scored for United, while three Portsmouth players scored own goals to add to the debt-ridden club's woes.
United will now hope Chelsea is beaten by third-place Arsenal on Sunday so the champions retain their one-point lead.
The top four regained a familar look after Liverpool climbed to fourth with a 1-0 victory over Everton, while Tottenham drew 0-0 with Aston Villa and Man City lost.
At Old Trafford, Wayne Rooney headed in from close range from Darren Fletcher's cross and Portsmouth defender Anthony Vanden Borre turned in Nani's attempted cross just before halftime.
After the break, Michael Carrick's shot deflected in off Richard Hughes before Dimitar Berbatov tormented the Pompey defense and fired home the fourth. Mark Wilson became the third Pompey player to score an own goal to round off the miserable day for the visitors.
United's crosstown rival City slumped to its second league loss since Roberto Mancini replaced Mark Hughes as manager in December as Hull climbed out of the relegation zone.
United States forward Jozy Altidore scored his first Premier League goal at his 18th game and George Boateng volleyed in Hull's second. Emmanuel Adebayor's goal for City wasn't enough to spark a comeback, despite Patrick Viera coming on as a substitute to make his debut for the club.
"In the first half we didn't play very well. Hull were more aggressive and put us under pressure," Mancini said. "In the second half we played very well, for me. When we brought on Patrick Vieira and Adam Johnson, the game changed. If we play like we did in the second half, we can arrive in the top four — but not if we play like we did in the first."
Liverpool remains ahead of City having bounced back following a lackluster start to the season by collecting 17 points from a possible 21 in the last seven matches.
Despite Everton defender Phil Neville clinging to him, Dirk Kuyt sent Liverpool captain Steven Gerrard's inswinging corner past goalkeeper Tim Howard from close range in the 55th minute for the game's only goal.
Liverpool was a man down from the 35th after Sotirios Kyrgiakos was sent off for a two-footed challenge on Everton midfielder Marouane Fellaini, who escaped punishment for stamping on the Greek defender in the same incident.
Everton winger Steven Pienaar was shown a second yellow card in the 90th for a light challenge on Gerrard, but the South African was fortunate not to be sent off in the first half for a foul on Javier Mascherano.
"Derbies are all about passion, commitment and fight, and we've beaten a good Everton side here with 10 men, so we should be proud and enjoy this," Gerrard said. "Our attitude prevailed, we stuck together and then took our chance when it came."
Burnley climbed out of the relegation zone and sent West Ham back into the bottom three with a 2-1 victory over the east London club.
Bolton is just one point above West Ham after drawing 0-0 with Fulham and Bolton is a further point ahead after holding Sunderland to a 1-1 draw.