Arsenal seized the initiative in the race for the top four with a 2-0 victory over Manchester United that inflicted the first league defeat of Ole Gunnar Solskjaer's tenure
Granit Xhaka forced an uncharacteristic goalkeeping error from David de Gea as his swerving shot fired the Gunners in ahead inside 12 minutes before Pierre-Emerick Aubameyang's penalty made sure of the victory midway through the second half
United hit the woodwork twice in the first half but there was a clear hangover from Wednesday's Champions League heroics in Paris as they suffered their first Premier League defeat December 16
Arsenal leapfrog United into fourth as a result of their ninth-successive home victory and move to within a point of third-place Tottenham as the top-four race intensifies with eight games to play
Arsenal had United under the cosh early on, registering three attempts, all of which were off target, inside the opening nine minutes, but United's first effort nearly yielded the opener
Luke Shaw strode down the left flank and picked out Romelu Lukaku in the Arsenal area, but the Belgian could only divert the ball onto the crossbar before Paul Pogba's attempted rebound was blocked
Arsenal then took a deserved lead, albeit in bizarre circumstances, as Xhaka swerving shot from 25 yards wrong-footed De Gea on its way into the middle of the United goal
Despite seeing little of the ball, United almost drew themselves level on 19 minutes as Fred took aim from the edge of the area and beat the outstretched arm of Bernd Leno, only to see his effort clip the post
Arsenal continued to pepper the United goal but lacked the killer touch, and they nearly paid the price on 36 minutes when Lukaku tried to round Leno, but the Arsenal goalkeeper made contact with the ball, forcing the striker to swipe at a shot which flashed across the face of goal
United almost drew level on the stroke of half-time as Pogba, Shaw, Lukaku and Dalot combined at pace on the counter and rolled the ball into the path of Rashford in the Arsenal area, but Xhaka intervened with a crucial block to preserve the Gunners' lead
Leno then came to Arsenal's rescue six minutes after the interval, racing off his line to confront Lukaku after Rashford's superb side-rule pass presented the Belgian with the chance to equalise, but the German diverted it onto the roof of the net
It looked as though United had settled into a rhythm that would cause Arsenal problems but, instead, the Gunners doubled their lead as Aubameyang - eight days on from his missed north London derby penalty - converted from 12 yards after Fred had bundled Alexandre Lacazette to ground
 an Arsenal supporter appeared to run into Chris Smalling as he invaded the pitch after Aubameyang's goal
 Lacazette should have put the game out of sight on 71 minutes with Arsenal's third but he fired wide after Victor Lindelof's misreading of the ball presented him with a clear route to goal, though it did not cost the Gunners as they saw out a comfortable victory
 "I'm very proud of our supporters, they pushed us a lot and this is a big result and they created a big atmosphere for our players
 United were in a good moment after one result against PSG but we had a big performance and we are in a good moment in the Premier League
 To take three points and get a good position for our target is very good and I'm happy for the players
" "We started slowly, maybe a backlash from Wednesday night, but we created chances and when they get the first goal it becomes a different game
 We created so many more chances than when we beat them in the FA Cup
 Sometimes it happens, we hit the woodwork twice and had five very big chances ourselves
 We just had to go for it towards the end, but we were not really at it and it is one of those days where you have to dust yourselves down from
"Arsenal look to overturn a first-leg deficit to reach the Europa League quarter-finals when they host Rennes on Thursday (8pm GMT)
 United travel to Wolves in the quarter-finals of the FA Cup on Saturday (7
55pm GMT)
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