Friedrich's blow piles more pain on Villas-Boas

Manuel Friedrich's header beats Petr Cech (AP)

And so the hangman tightens his noose. Talk of Andre Villas-Boas's execution after just 16 weeks as Chelsea manager might have seemed premature, almost paranoid, but after his side's hopes of progress in the Champions League were jolted as their Premier League dreams have been, the Portuguese will feel Roman Abramovich's breath on his neck.

Once again, his high line has placed him on the high wire. Chelsea looked safe when his defence went AWOL, allowing Eren Derdiyok to cancel out Didier Drogba's opener. Arne Friedrich headed home in stoppage time. Villas-Boas must now beat Valencia to be certain of reaching the latter stages of this competition. Anything less, and his head is on the block.

Chelsea came into this game shorn of conviction. Lars Bender and Simon Rolfes overpowered Raul Meireles and Frank Lampard in the middle. A pace further forward, Michael Ballack, even in the autumn of his career, showed his customary cocksure strut. It was the 35-year-old who went closest to threatening his old club, heading Gonzalo Castro's corner onto the bar.

That stirred Villas-Boas's side into action. They ought to have had a reward before half-time, Frank Lampard dawdling after Juan Mata's inviting pass. No matter; immediately after the break, Drogba conjured a lead, shielding Daniel Sturridge's pass and drilling the ball past Leno.

But again Chelsea's destruction was of their own making. Sturridge allowed Sidnei Sam to ghost in to space down Chelsea's right side with not even a semblance of a marker near him; both Ivanovic and Alex had disappeared as the winger raced toward goal; Cech stood between his line and the advancing forward as though his feet were encased in concrete. All were guilty as Sam crossed and Derdiyok headed in.

True, Chelsea should have had a penalty when Friedrich tripped Drogba, but this is a team hamstrung by mental fragility. Friedrich headed in almost unmarked at the death.The case against Villas-Boas mounts.