|United's Brazilian midfielder Anderson had to clear off his own goal line in the first half [AFP]|
Arsenal remain one point clear at the top of the English Premier League after winning 1-0 at home to London rivals, Chelsea, in a combative match.
Earlier in the day Manchester United had gone top due to a 1-0 win away to Liverpool, but Arsenal's victory put United back into second place.
A header by Arsenal captain William Gallas, against his old club, won the game for Arsenal.
With the last chance of the first half, Chelsea goalkeeper Petr Cech missed a corner cross in the six-yard box and Gallas headed the ball in for Arsenal.
Arsenal's midfield trio of Cesc Fabregas, Mathieu Flamani and Alexandar Hleb came back into the team after injury at a lively Emirates Stadium.
Chelsea, who had only conceded one goal in their last nine Premier League games, lined up with an out-of-form Andriy Shevchenko in attack in the absence of Didier Drogba, who is recovering from knee surgery.
High tempo match
Arsenal put Chelsea under pressure early on with sharp offensive play. Adebayor caused confusion in the Chelsea defence when chasing a long ball, forcing Alex to head over an advancing Cech but the ball went wide.
The game was played to a high tempo with quick, intricate passing leading to tough tackling by both sides.
In the first half hour scuffles broke out as John Terry, the Chelsea captain, flew into a challenge with Fabregas.
A dipping, long-range effort by Shevchenko on 32 minutes was unconvincingly dealt with by Arsenal goalkeeper Manuel Almunia, as the two sides became more belligerent.
Then, on half-time, Arsenal scored. Chelsea missed centre-back Terry - who had earlier been substituted due to injury - at the corner as Gallas was not sufficiently pressurised for the header.
In the second half Shaun Wright-Phillips had the clearest opportunity of the game. A cross from the left cut out the Arsenal defence but Wright-Phillips could only volley the ball wide of Almunia's right-hand post from four yards out.
Going into the last 15 minutes Arsenal caught an attacking Chelsea on the break. Hleb was put through and laid the ball on to substitute Van Persie 17 yards out in the centre of the goal, but the ball was smacked over the cross bar.
Chelsea heaped pressure on to the Arsenal defence, but could not find an opening.
As they pushed forward Arsenal counterattacked and a double save by Cech from Van Persie and then Fabregas prevented Arsenal from taking the victory early.
Five minutes of extra time gave Chelsea an opportunity with a drive from a Shevchenko free kick that was tipped over the bar by Almunia.
Fabregas had one last chance for Arsenal 10 yards out but his weak effort rebounded straight off Cech before the final whistle was blown.
Meanwhile at Anfield a goal from Carlos Tevez towards the end of the first half gave United a win against Liverpool on Sunday.
The game lacked opportunities and quality despite the two teams beginning the day in second and fifth positions respectively.
Owen Hargreaves replaced Michael Carrick in midfield for United, while Liverpool were unchanged from the side that beat Marseille in the Champions League in mid-week.
In a tight first 30 minutes Liverpool came closest. A goal mouth scramble saw a Harry Kewell shot cleared off the line by Anderson and Fernando Torres head the rebound just wide after goalkeeper Edwin Van der Sar flapped at a cross.
Three minutes later the United defence was in disarray again as Van der Sar slipped under a high cross and Ferdinand's resulting header went backwards, requiring Patrick Evra to clear the ball from in front of his own goal.
Tensions were high with bookings for Evra, Wes Brown, Anderson and Alvaro Arbeloa in the first half.
United failed to threaten the Liverpool goal until the 43rd minute, when a corner played to the edge of the Liverpool penalty area was hit low by Giggs into a mass of players.
Tevez got the last touch flicking the ball into the top of net from three yards.
Liverpool pressed for an equaliser in the second half but were only able to come close with a Ryan Babel effort from the edge of the penalty area on 75 minutes, which whizzed past Van der Sar's left hand post.
Liverpool's attacking was laboured and failed to produce any telling efforts, with the United defence standing up.
Wanye Rooney next found himself unmarked at the far post after United broke but put his shot wide. It was one of only a few chances for United.
Liverpool captain Steven Gerrard put a free kick just over the top left of the cross bar in injury time.
But his side had failed to create any meaningful openings and remian in fifth position behind fourth and third placed Manchester City and Chelsea respectively.