Tomas Rosicky scored twice to help lift Arsenal into the Champions League places as the 10-man Gunners held on for a 2-1 win over West Brom at the Hawthorns.
Arsenal had looked in complete control after Rosicky put them 2-0 up with his second goal early in the second half but when Per Mertesacker was sent off after conceding a penalty that James Morrison converted with 19 minutes remaining the game hung firmly in the balance.
But West Brom failed to take three good chances in the closing stages as Arsenal escaped to move above Chelsea into the top four on the ground where they secured Champions League qualification on the final day of last season.
With Romelu Lukaku starting on the bench, Shane Long was all too often isolated in attack leaving West Brom struggling to create in the final third for much of the match. Their best effort of the first half came in a brief spell of pressure in the early stages as Claudio Yacob flashed a near-post header at goal but Rosicky was handily placed on the post to head off the line.
And a few minutes later the Czech would have a crucial intervention at the other end. Gervinho, so impressive against Reading last week, had a crucial part to play as he raced onto a long pass over the top from Mikel Arteta and cut inside from the left before curling a ball toward the far post that Rosicky reacted instinctively to with a header to divert it past Ben foster.
Arsenal continue to looked comfortable, but out of nothing were lucky not to concede a penalty. Laurent Koscielny lashed a leg to try and clear on the edge of the box, but the Frenchman got nothing of the ball and plenty of Jacob on his follow through, but referee Howard Webb waved away the home protests.
Almost on the stroke of half time, Arsenal should have doubled their lead with their best move of the match. Santi Cazorla fed an intricate through ball to Olivier Giroud and instead of shooting the striker back-heeled the ball perfectly into the stride of Ramsey clean through on goal, but somehow the Welshman poked his shot wide of the target.
Thankfully for Ramsey and Arsenal’s Champions League hopes, the miss was quickly forgotten as Arsenal applied the pressure at the start of the second half. Bacary Sagna came close to getting on the score sheet as he burst forward onto Gervinho’s pass but Foster got out to him in time to block the full-back’s shot.
And five minutes after the interval, Arsenal and Rosicky grabbed their second goal of the encounter.
Receiving a pass inside from Ramsey on the edge of the box, Rosicky, so blighted by injury in recent seasons, controlled the ball brilliantly with his first touch before firing a volley at goal that Foster blocked away but the midfielder made no mistake in drilling the follow up low into the corner.
That appeared to be that in terms of Arsenal securing a vital three points, but the game was blown wide open in the final 20 minutes.
A good ball over the top went right into the stride of Long and just as he looked poised to pull the trigger, Mertesacker came in with a desperate lunge from the side to take down the Republic of Ireland striker and this time the referee elected to point to the spot and also gave the German his marching orders.
Morrison took the spot kick and, although it was far from the cleanest effort, it just squeezed past Lukasz Fabianski.
The incident completely altered the momentum of the contest as West Brom piled on the pressure. They created three good chances too but Gareth McAuley headed into the side netting, Lukaku blasted inches wide of the post and Long fired over the bar.
Arsene Wenger will be concerned at how his side relinquished control of the match late on but ultimately at this stage of the season he will be relieved simply to be walking away with the three points.