Arsenal moved back into third place in the Premier League with an unconvincing London derby win over 10-man Fulham.

The Gunners dominated early on and seemed to have been gifted a path to victory by Steve Sidwell's 12th-minute dismissal for a lunge on Mikel Arteta.

But Fulham posed the greater threat and Arsenal were fortunate to lead at half-time through Per Mertesacker's header.

They continued to struggle but held on despite Olivier Giroud's red card for a last-minute lunge on Stanislav Manolev.

Fulham played like lions - Jol

That evened the numbers up for a thrilling period of injury time in which the Cottagers came close to salvaging an unlikely but deserved draw and denting the visitors' chances of finishing in the Champions League places.

A surging early run from Manolev apart, Fulham had barely got out of their own half before Sidwell's dismissal for his needless challenge.

Sidwell had only returned to the side after serving a three-match ban and his moment of madness seemed likely to lead to an Arsenal onslaught.

But following his red card, Fulham were the better side for long spells. They made full use of their pace on the counter-attack and Dimitar Berbatov's ability to link up play, and they could easily have gone ahead.

Fulham, who have now picked up just one point from their last four matches, already looked intent on sitting deep and frustrating opponents who had failed to break down a resolute Everton defence in midweek.

Sidwell's sending off ensured they had little option but to play on the break, and although Fulham slipped to a second successive derby defeat in the space of four days, they looked the more likely to score in open play.

Gunners in charge Arsenal have now won 16 of the 24 Premier League meetings between the two sides but this was their first victory in five, since a 2-1 home success in December 2010.

Berbatov had a fierce strike beaten away by goalkeeper Wojciech Szczesny after a brilliant 40-yard run and pass by Bryan Ruiz.

And Alex Kacaniklic, recalled from a loan spell at Burnley to ease an injury crisis, twice caused problems after a threatening run forward.

The Gunners, who have now won eight of their last 10 league games, looked ponderous and, although dominating possession, were struggling to create chances.

Giroud came closest to breaking the deadlock with a fine low strike across goal that hit the outside of the post after good work by Santi Cazorla.

They did take the lead just before the break from a Theo Walcott set-piece when Mertesacker headed home from close range after Laurent Koscielny's mistimed header across goal.

However that did not relax the visitors, who looked increasingly edgy during a lifeless second half, devoid of clear chances.

Fulham's Steve Sidwell lunges in on Mikel Arteta

Fulham continued to threaten on the counter-attack and Manolev, after one such break, thought he had equalised but was offside when he turned the ball in on the rebound after Szczesny saved Kieran Richardson's free-kick.

But despite a sloppy second-half display, Arsenal withstood the late pressure after Giroud's red card to move two points clear of fourth-placed Chelsea - although they have played two more games than the Blues.

Fulham manager Martin Jol: ""I was annoyed with him [Sidwell], but he says it is not intentional. He will regret that tackle. It was the first foul that spoilt the game.

"I know it was not intentional because he wanted to play. He has just come back from a three-match suspension and now he is out for another four matches again so it was not only disappointing for him, but also for us because we had to play with 10 men for a long time.

"But we fought like lions and had better chances than them. In the first half we did ever so well but conceded a soft goal."

Arsenal manager Arsene Wenger: "I think the referee could only give a red card [to Sidwell]. We will see [if Arteta is okay]. He played the second-half. I don't know how much damage is done. It is a kick, a bad kick.

Arsenal on sensational run - Wenger

"I don't know if he has twisted his ankle or not. In these kind of things it is a question of a fraction of a second. If you are fully on your foot at the moment you get it you break your leg. If you ease a bit off maybe that is why he got away with it.

"We had a positive first half but in the second half we became sloppy with our passing and played with less pace to our game.

"You have to give Fulham credit; they are a good side and they played very well. It became hard in the second half. We played with the handbrake on and tried to keep the lead without taking risks. We didn't give them enough problems. We lost pace and quality."