(CNN) -- Chelsea moved five points clear in the English Premier League after claiming a controversial 1-0 victory at home to defending champions Manchester United on Sunday.
The Londoners' captain John Terry was credited with the winning goal, though his header in the 76th minute appeared to take a deflection off teammate Didier Drogba.
United were left furious, claiming that the free-kick from midfielder Frank Lampard that led to the goal should not have been awarded, with Darren Fletcher ruled to have fouled defender Ashley Cole despite winning the ball.
United manager Alex Ferguson also claimed that Chelsea striker Didier Drogba fouled Wes Brown before trying in vain to make contact with Terry's header in what seemed like a marginally offside position.
"Clearly, Darren Fletcher's won the ball -- Ashley Cole was never touched and has jumped up in the air -- and then Drogba's pulled Brown to the ground for the goal," he said.
"The referee's position to make the decision was absolutely ridiculous, he can't see anything. He's got a Chelsea player [Joe Cole] standing right in front of him and he doesn't even move. It was a bad decision, but there's nothing we can do about it."
United were also disappointed not to be awarded a first-half penalty when a tumbling Terry appeared to drag Antonio Valencia down with him by tugging his shirt.
Valencia was lucky not to be sent off late in the game as tempers flared, with referee Martin Atkinson handing the winger a yellow card for his two-footed tackle on Lampard.
The result left Chelsea on 30 points with 10 wins and two defeats from 12 games, with second-placed Arsenal ahead of United on goal difference.
It was United's second defeat in three weeks against traditional top-four rivals following the 2-0 defeat at Liverpool.
But it ended a successful week for Chelsea, who had their worldwide transfer ban suspended pending a ruling on their appeal by the Court of Arbitration for Sport.
Matthew Etherington put the visitors ahead in the 29th minute, but Seyi Olofinjana leveled against his former club with a similarly fine effort from the edge of the penalty area on 62.
Stoke lost midfielder Abdoulaye Faye to a second yellow card moments before Dutch substitute Jan Vennegoor of Hesselink snatched the winner in the final minute after Jimmy Bullard's shot was only parried by goalkeeper Thomas Sorensen.
French striker Louis Saha returned from injury to score the opener against the run of play on 26 minutes, and Dan Gosling doubled the lead 15 minutes after halftime, but Tom Hibbert's late own-goal set up a tense finish.
Defender Emmerson Boyce put the home side ahead in the 14th minute after Paul Scharner headed the ball across the goal, but American midfielder Clint Dempsey rescued a point with a penalty six minutes before halftime after being fouled by Titus Bramble.