Diego Costa once again proved to be Arsenal's undoing with the Chelsea man scoring the only goal as the reigning Barclays Premier League champions beat the 10-man Gunners yesterday.
Having tussled with Gabriel and Laurent Koscielny in September's reverse fixture at Stamford Bridge, Costa was again the villain of the piece from an Arsenal perspective as he proved the catalyst in Chelsea's 1-0 win - a result which leaves the Gunners in third behind both Leicester and Manchester City.