Frank Lampard showed the nerve which has made him one of England's finest players to rescue a point which takes Chelsea four points clear at the top of the Barclays Premier League at Christmas.
Lampard, once hailed but now routinely jeered inside the Upton Park ground he graced as a youngster, slotted home a penalty in the second half which he was forced to take three times.
Some players might have been thrown by that. Lampard simply kept rippling the back of West Ham goalkeeper Robert Green's net until referee Mike Dean finally signalled the goal which cancelled out a first-half penalty by Alessandro Diamanti.
But if it signalled two dropped points for Chelsea in their quest for the title, then for West Ham manager Gianfranco Zola perhaps this was the corner he has been waiting to turn.
The corner which means the Hammers will not be bottom on Christmas Day, which is usually a prelude to relegation.
Instead, Zola can forget bringing in a psychologist, as he had admitted thinking of, to boost the confidence of his West Ham players.
All he needs to do is show them the video of this battling performance, when at last they added grit to their undoubted style.
Maybe the improvement was sparked by the fact that Zola was facing his old club and opposing manager Carlo Ancelotti, with whom he used to play for Italy.
You certainly could not fault West Ham's work rate, nor their readiness to play football. They were committed to the fluent, passing, scampering style of play for which Zola has always been famed.
Scott Parker, in particular, was a terrier in the centre of midfield. So was Jack Collison, while Guillermo Franco was a threat up front.
True, Chelsea, with Joe Cole and Lampard back on the ground where they learned their football, always had more physical power.
They might have taken the lead after 22 minutes when Branislav Ivanovic's powerful header from a corner was chested off the line by Parker.
Lampard, who received a predictably hostile reception, also spurned a good chance when he fluffed a left-footed shot from eight yards.
But it was West Ham who took the lead and no-one could say they did not deserve it, even if it was via the penalty spot.
Collison surged at the heart of Chelsea's defence and as he bore down on goalkeeper Petr Cech, England full-back Ashley Cole slid in.
The tackle needed to be perfect. It wasn't and referee Mike Dean had no hesitation pointing to the spot to allow Diamanti to send Cech the wrong way.
Cue the sort of Upton Park euphoria which has been in scarce supply this season.
It must have been an easy half-time team talk for Zola. Carry on playing as you are.
And they tried to, snapping and harrying the blue shirts with a tenacity which made a nonsense of their lowly league position.
They were undone by what looked like a dodgy refereeing decision from Mr Dean, who pointed to the spot when Matthew Upson tackled Chelsea substitute Daniel Sturridge.
It looked as if he took the ball, a message he attempted to deliver to the assistant referee when he raced to the touchline miming the shape of a football.
No matter, Lampard took the spot kick and scored, only for it to be scratched by the referee for encroaching players. Lampard tried again and scored again, only for the picky Mr Dean to order the kick to be retaken once more.
To Lampard's credit he did not let it upset him, stroking the ball home once more and this time the referee did point to the halfway line.
West Ham could have let their heads drop as they have done in recent months when faced with adversity.
But they did not and it took a diving save from Cech in the 72nd minute to beat away a powerful left-foot shot from the lively Diamanti.
They also found the resilience to keep out a surging Chelsea finish.
"Things can change very quickly in football," Zola told the fans in the matchday programme.
He was right. Now the Hammers need a lot more of the same.Reuse content