Sunderland - Olivier Giroud came off the bench to score twice in five second-half minutes as Arsenal maintained their Premier League title challenge with a comfortable 4-1 win at struggling Sunderland.
Alexis Sanchez scored the Gunners' other two goals to make it 14 games unbeaten for Arsene Wenger's side, who would have won with even more to spare had they taken all their chances in a dominant display.
Sunderland momentarily looked capable of springing a surprise when they levelled through Jermain Defoe's 65th-minute penalty.
But their unlikely comeback was short-lived as Giroud claimed his first Premier League goals since May to herald a decisive burst of three goals in six and a half minutes from the visitors.
The Frenchman had been on the pitch for just 60 seconds when he volleyed home a cross from Kieran Gibbs to restore Arsenal's lead in the 71st minute.
The 30-year-old secured victory with a looping near-post header from a Mesut Ozil corner soon after, before Sanchez kept his composure to add a close-range fourth after Gibbs's shot came back off the post.
Arsenal provisionally moved three points clear at the league summit ahead of the rest of Saturday's games.
Defeat left winless Sunderland bottom of the table and with two points from 10 games, they have matched Manchester City's unwanted 1995 record for the worst start to a Premier League season.
Manager David Moyes is still searching for a first league victory since succeeding Sam Allardyce in July.
The visitors should have had more than Sanchez's first league goal since the end of September to show for their dominance before the break.
Sunderland were fortunate not to concede half a dozen goals by half-time as they were left chasing shadows by Arsenal's slick passing and movement.
The Gunners barely missed Theo Walcott, their eight-goal joint top scorer rested to protect a minor injury, as they deservedly took a 19th-minute lead.
It arrived at the culmination of a 22-pass move that was an exercise in retaining possession.
Sanchez stole in front of a statuesque Lamine Kone to send a glancing header into the far corner from an Alex Oxlade-Chamberlain cross.
Ozil should have scored either side of Sanchez's strike, first aiming a tame angled drive at Jordan Pickford after being the beneficiary of a sumptuous pass from the Chilean.
Later on in the half, Ozil's weak lob was easily saved by the Sunderland goalkeeper after the German playmaker had been put clean through by Oxlade-Chamberlain.
Alex Iwobi curled an effort narrowly over from distance after Arsenal again caught their hosts on the counter-attack when Patrick van Aanholt surrendered possession deep in opposition territory
But while the deficit remained at a single goal, Sunderland retained hope.
Van Aanholt curled an early free-kick narrowly wide after a foul on Wahbi Khazri and although Defoe had the ball in the net before half-time, the forward's effort was rightly ruled out for offside.
Arsenal should have had a penalty when Sanchez was brought down by a labouring Kone after the interval.
Within seconds at the other end, Sunderland were given an unexpected chance to level from 12 yards as Petr Cech earned a yellow card for bringing down Duncan Watmore as he bore down on goal.
Defoe sent the Arsenal goalkeeper the wrong way to bring Sunderland level.
But Giroud found the net in the Premier League for the first time since his final day hat-trick against Aston Villa five months ago and Wenger's men did not look back.