A hotly contested goal from Nani helped Manchester United beat Tottenham 2-0 and stay within five points of Chelsea after the English Premier League leaders fought back to beat Blackburn 2-1 on Saturday.
Arsenal is also five points adrift of champion Chelsea after Alex Song's 88th-minute header clinched a 1-0 victory over bottom-place West Ham.
Manchester City, though, is three points further behind after relegation-threatened Wolverhampton inflicted the second straight loss on the league's biggest spenders.
While Wolves provided Saturday's big shock, Old Trafford was the scene of the biggest controversy.
United was already leading through Nemanja Vidic's 31st-minute header when Nani netted in the 84th.
The Portugal winger had originally unsuccessfully appealed for a penalty and then used his hand to casually control the ball after falling.
Spurs goalkeeper Heurelho Gomes placed what he believed to be a dead ball down to take a free kick, but as he prepared to take it Nani swooped in and poked the ball into the net.
Referee Mark Clattenburg's assistant on the right flank initially appeared to rule out the goal. But he was overruled by the senior official after consultation, sparking furious protests from the Tottenham players.
"It was handball. He put his hand on the ball and dragged it down," Spurs manager Harry Redknapp said. "He should have been booked. The referee didn't see him handball it, that's why he's allowed play to go on.
"The assistant referee has seen it, that's why he's flagged. He's (Clattenburg) gone over and he's told him what he did, he should disallow the goal."
United manager Alex Ferguson said the original penalty should have been awarded and then added that Gomes "should know better. He's an experienced goalkeeper. I thought he made a mess of it."
"The referee played on because the goalkeeper took possession of the ball," Ferguson said. "He then went to take a free kick thinking it was a foul. He made an error."
At Ewood Park, Chelsea came under intense pressure from the start and lax defending meant it was fortunate not to have conceded before Benjani Mwaruwari did put Blackburn ahead in the 21st.
Benjani rose above Chelsea captain John Terry and met El Hadji Diouf's cross with a downward header to claim his first goal of the season.
But Nicolas Anelka leveled in the 39th, sweeping home after Didier Drogba headed on Florent Malouda's cross.
The recovery was completed in the 84th when Branislav Ivanovic met Yuri Zhirkov's cross at the far post.
"We were a little bit lucky," Chelsea manager Carlo Ancelotti said. "To win here was important because they were better. We were not great again. Blackburn put us under some pressure and we were not able to play our football.
"We knew it would be difficult to win here because Blackburn are a very good team with a lot of strength and physical ability and long balls."
Arsenal's winner came even later at Emirates Stadium, with Song diving in to head home Gael Clichy's cross in the 88th. Samir Nasri and Theo Walcott had earlier been frustrated by the cross bar.
West Ham stayed rooted to the foot of the table on just six points, with the loss increasing the pressure on manager Avram Grant.
Man City looked to have recovered from its setback last weekend when Emmanuel Adebayor's first goal of the season from the penalty spot put the visitors ahead in the 23rd. Wolverhampton defender Richard Stearman conceded the spot kick by fouling David Silva.
But Nenad Milijas leveled for Wolves on the half-hour and David Edwards added the winner in the 57th by slotting a rebound past goalkeeper Joe Hart into the right corner
At Craven Cottage, Clint Dempsey's double lifted Fulham up eight places to eighth.
The United States forward headed in a cross from Carlos Salcido on the half-hour before adding his second by meeting Chris Baird's pass for a powerful finish in the area.
Everton stretched its unbeaten run to five matches thanks to Aiyegbeni Yakubu's first goal of the season, while condemning Stoke to its fourth straight loss.
Yakubu beat goalkeeper Asmir Begovic in the 67th after Tim Cahill's shot rebounded off the post.
