Arsenal produced a polished performance to beat Birmingham 3-0 at St Andrews and stay in touch with the Premier League’s top two.
A pulsating first half full of chances and controversy ended with the Gunners holding a slender edge thanks to Robin van Persie’s deflected free-kick on 13 minutes.
Van Persie was very much the central figure early on as Birmingham felt he had gone down too easily to win the set-piece, with the Dutchman then fortunate not to concede a penalty when the ball struck his outstretched arm inside the Arsenal box.
Van Persie also missed a glorious opportunity to make it 2-0, while Roger Johnson blazed a volley over Lukasz Fabianski’s crossbar at the other end from close range.
Johnson had earlier been shown just a yellow card for a mistimed tackle on Cesc Fabregas and Lee Bowyer escaped punishment for a stamp on Bacary Sagna as the second half started in a similarly competitive manner.
But Arsenal began to break down Birmingham’s resistance and turn on the style as the match progressed, with Samir Nasri curling a sumptuous second past Ben Foster just before the hour mark.
Foster had to pick the ball out of his net for a third time before the final whistle when Johnson scored an own goal following a slick Gunners move.
Birmingham were left chasing shadows in the closing stages as they went down to a rare home defeat that leaves them second bottom, while Arsene Wenger’s men remain just two points behind Manchester United and Manchester City.