Has slump gone too far for champions to recover?
But the Gunners' emphatic 3-1 success over the Premier League champions on Monday night at the Emirates not only extended their recent slump to crisis point, it throws doubt over whether they can possibly recover to mount a challenge for the title.
At one stage, Chelsea held a five-point lead at the top of the table - now, after a run of one win in eight Premier League outings, they trail leaders Manchester United by six points and lie fourth.
It's not just a slip in the league - Chelsea have won only twice in their last 10 matches in all competitions; against Fulham (currently the only Premier League team on a worse run of form than the Blues) and Champions League minnows MSK Zilina.
So can Chelsea right the ship and salvage their title ambitions - or has it already slipped away from them?