By Chris Harris at Emirates Stadium
Olivier Giroud returned with a brace as Arsenal cruised to victory over Sunderland at Emirates Stadium.
The France striker steered a low finish past former Gunner Vito Mannone after five minutes and then latched onto a poor backpass from Santiago Vergini to double the home side's lead after half an hour.
The piece de resistance came just before the break when Tomas Rosicky rounded off a team goal to rival the one Jack Wilshere converted against Norwich earlier this season. This time Wilshere and Giroud were involved in the build-up before Rosicky applied a clever finish.
It was a goal even Dennis Bergkamp would have been proud of. Fittingly he was looking on, hours after a statue of the Dutchman was unveiled outside Emirates Stadium to recognise his contribution to the Club.
Laurent Koscielny headed home a fourth early in the second half before Emanuele Giaccherini hammered in a late consolation for Sunderland - the first time Arsenal have conceded at home in the league for eight hours and 57 minutes.
That was a blip on a very comfortable afternoon for Arsene Wenger's side, who stay just one point behind Chelsea at the top of the Premier League.
For all the talk of February being decisive, it now seems that March will be the month that defines Arsenal season. With 10 games to go, the title remains well within reach.
SETTING THE SCENE
Before the game Wenger had spoken of the need to overcome any "negative vibes" after the midweek defeat to Bayern Munich. The gruelling nature of that match prompted the manager to freshen up his starting XI with five changes.
Mesut Ozil was rested completely while Kieran Gibbs was sidelined by injury. In came Nacho Monreal, Rosicky, Lukas Podolski, Giroud and Mikel Arteta - the latter after serving a European suspension.
There was a familiar face in the Sunderland goal - Mannone - and the Capital One Cup finalists arrived in north London in fine fettle, unbeaten in their last six matches on the road and thriving under new manager Gustavo Poyet.
Chelsea's last-gasp winner against Everton in Saturday's early kick-off left the Premier League leaders four points ahead of Arsenal. If not must-win, this was surely must-not-lose.
And the Gunners made a perfect start.
Sunderland's gameplan was obvious - defend deep and in numbers, crowd out Arsenal's creative players and look to strike on the counter-attack. But the plan was in tatters within five minutes.
A patient build-up was suddenly quickened as Wilshere found Podolski, he fed Rosicky and the Czech's first-time flick picked out Wilshere, who had continued his run. Bardsley got a toe in as the midfielder shaped to shoot and the loose ball fell invitingly for Giroud, who steered it past Mannone.
It's was Giroud's 11th league goal of the season - matching last season's tally with 10 games to spare.
Arsenal were clearly in the mood. Cazorla was the next to threaten with a low shot after Rosicky picked him out just inside the area, but Mannone saved comfortably. And Giroud almost found Podolski with an audacious flick following Cazorla's raking cross-field pass.
Sunderland, forced out of their shells, had their moments too. One of many fast breaks saw Marcos Alonso race into space on the left and cross towards Fabio Borini, but Wojciech Szczesny anticipated well.
The visitors looked lively but Mannone remained the busier of the two keepers. The Italian did well to palm a vicious effort from Podolski over the bar before comfortably holding Rosicky's long-range shot. But he was helpless when Sunderland hit the self-destruct button on the half-hour.
Vergini was the culprit with a woefully under-hit backpass and Giroud nipped in to slot the ball under Mannone.
Arsenal scented blood. Sagna tried his luck from 30 yards and Podolski hammered in a free-kick from much closer - both were deflected wide. The third goal wasn't far away - and it was one to savour.
Rosicky picked up possession on the right and exchanged passes with Wilshere before feeding Giroud, collecting his return flick and lifting the ball over the advancing Mannone. Shades of Wilshere's goal against Norwich and a breathtaking way to end the half.
Poyet rang the changes at half-time, introducing former Gunner Sebastian Larsson and Giaccherini. And Wenger tweaked his defence, giving Monreal a rest, moving Sagna to left back and bringing on Carl Jenkinson.
With Poyet's words no doubt ringing in their ears, the visitors had a go and almost caught Arsenal resting on their laurels.
Per Mertesacker was called into action with two desperate clearances as Sunderland got men into the box, and Szczesny made a terrific reaction save to keep out Borini after he had turned Mertesacker.
Sunderland almost did score the next goal - but at their own end. Once again Vergini was found wanting as he scooped an attempted clearance just wide of Mannone's post.
The respite was brief. From the resulting corner, Koscielny rose unmarked to head home a fourth and put the result beyond doubt. The Frenchman was taken off soon afterwards after picking up an injury. One negative on a day of positives.
With Mathieu Flamini slotting in at left back and Sagna in the centre, Arsenal's back four had an unfamiliar look, and they were almost breached when Ki Sung-Yueng forced a sharp stop from Szczesny.
Larsson also went close with a trademark free-kick but the home side also had chances to extend their lead, most notably when Wilshere put substitute Serge Gnabry through, only for Mannone to block well.
There was one final goal, a cracking long-range strike from Giacheerini, but it didn't take the gloss off a polished Arsenal performance.
Referee: Andre Marriner
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