Birmingham 0-3 Arsenal
Birmingham always look to rough Arsenal up. In 2008 Martin Taylor overstepped the mark and broke Eduardo's leg. This time there was an early, reckless lunge by Roger Johnson that could have done Fabregas damage. Arsenal responded well, kept playing their football and won comfortably.
Birmingham might lack flair but it is not just their physicality that makes them a tough proposition. They defend deep, almost never letting a team get behind them, and their home record shows that they usually succeed in keeping games tight even against far superior opposition.
Van Persie's opener was a vital moment because it meant Arsenal could play the rest of the game on their own terms. He dived when running onto Fabregas's sideways pass. The referee bought it, and the Dutchman's free kick hit Lee Bowyer and bounced past Ben Foster.
The game should have been over by half time, but it could have been level if the ref had spotted Van Persie's clumsy handball in the Arsenal penalty area. The same man was wasteful when he twice spurned point blank opportunities at the other end.
In the second half Birmingham offered no threat, but Arsenal continued to waste chances, until Nasri and Fabregas exchanged pinball passes and the Frenchman buried the ball inside Foster's near post from the edge of the area. The third, an own goal, was the result of more bewildering interplay between Arsenal's two best players, whose understanding seems to be growing.
Their creative capacities will be tested again on Wednesday. The match between Arsenal and City looks at the moment like a 2nd place playoff but either team would gain a lot of belief from a positive result.
They will both be disappointed that Manchester United were let off the hook by a wasteful West Brom during Saturday's lunchtime game. United benefitted from chickenshit refereeing from Chris Foy, when Gary Neville took out Graham Dorrans and appeals were waved away- no penalty, no red card. Then they benefitted from the hosts' profligacy when Foy did blow up for Rio Ferdinand's ill-timed swipe on Jerome Thomas. Peter Odemwingie sent a pathetic penalty yards wide.
That made United's winner seem inevitable, despite the poverty of their performance, and it arrived through Javier Hernandez, who continues to show the ability to turn tight games in United's favour.