Bryan Ruiz missed the crucial spot-kick as 10-man Chelsea moved into the fourth round of the Carling Cup with a penalty shootout win over Fulham.
The final kick struck the underside of the bar and bounced on - but not over - the line to hand Chelsea victory in dramatic fashion.
Fulham came closest to scoring in normal time when Pajtim Kasami hit the crossbar with his 49th-minute penalty.
It was awarded after Kerim Frei was hauled down by Alex, who was sent off.
Chelsea boss Andre Villas-Boas fielded a young line-up, handing starts to Romelu Lukaku and Josh McEachran - with the later creating the best chance of the first half.
McEachran brilliantly burst into the box and beat Fulham goalkeeper Mark Schwarzer, but with Daniel Sturridge making sure by tapping the ball over the line he was flagged offside.
Sturridge pulled up sharply in the first half with what appeared to be a hamstring injury. Goalkeeper Petr Cech was also hurt when he collided with Orlando Sa, and failed to emerge after the break.
No sooner had the second half got underway than Fulham won a penalty.
Ruiz's clever back-heel freed debutant Frei, who was brought down by Alex. The Brazilian protested his innocent but was dismissed by Chris Foy before Swiss teenager Kasami hit the bar with his penalty.
A frantic second half saw good chances missed at both ends, with Frei and Kasami clearing off the line from a corner before the former's finish sailed wide at the other end under pressure from substitute keeper Ross Turnbull.
The game drifted into a penalty shootout, which saw Frank Lampard miss for Chelsea and Moussa Dembele for Fulham also failing.
New Fulham striker Ruiz missed the crucial kick in controversial circumstances, with the ball bouncing on the line after it had struck the underside of the bar - but the officials judged that the ball did not cross the line and the Blues progressed.
Chelsea's win improved their miserable record of seven penalty shoot-out defeats from their previous eight.
Chelsea manager Andre Villas-Boas on the Ruiz penalty:
"Everybody was looking at each other wondering if it was celebration time.
"The linesman was there so maybe, this time, the decision is good."
He added: "It was a superhuman effort during 70 minutes.
"To be with 10 men for 70 minutes and to hold Fulham's goal and still to create the most amount of opportunities and the best opportunities is out of this world.
"I'm very, very happy with the display of everybody, commitment-wise, effort-wise, concentration-wise."
Fulham boss Martin Jol on the Ruiz penalty:
"To be fair, I haven't seen it.
"Somebody was standing in front of me and then I saw him [Ruiz] go towards the goalkeeper and I knew that he'd missed."