Substitute Daniel Sturridge struck late in extra time as 10-man Chelsea edged out an Everton side also a man down 2-1 in the Carling Cup.
Chelsea went ahead through Salomon Kalou after a dreadful error by back-up goalkeeper Jan Mucha but were pegged back by Louis Saha after their number two keeper Ross Turnbull was sent off.
Yet Everton wasted numerous chances to win in normal time and, after losing Royston Drenthe in extra time, Sturridge settled the fourth-round tie after 116 minutes. It was a remarkable contest in which both sides missed a penalty, Nicolas Anelka firing wide early on and Petr Cech, on after Turnbull's indiscretion, saving from Leighton Baines.
Chelsea made 10 changes as they fielded a largely second-string team, but manager Andre Villas-Boas packed his bench with senior players as insurance. While the likes of Frank Lampard, Fernando Torres and Juan Mata were also on the bench, captain John Terry, who is currently the subject of a racism investigation, did not travel.
Chelsea should have taken the lead after John Heitinga conceded a penalty by hacking down Josh McEachran. But Anelka lacked conviction as he plodded up to the spot and side-footed wide.
Mucha was inexplicably troubled by an innocuous shot as Chelsea were gifted the lead after 38 minutes. The Slovakian seemed in little danger as Kalou gently lobbed the ball at him from 18 yards, but he somehow allowed it to squirm through his grasp and his frantic effort to recover proved in vain.
Everton were almost caught napping early in the second half as Anelka found space only to shoot at Mucha, but Turnbull then suffered his moment of horror to allow Everton back into the game. David Luiz failed to cut out Tim Cahill's flick and Saha instinctively touched the ball past Turnbull, who chopped him down.
Referee Lee Mason pointed to the spot and brandished a red card, but Cech immediately made amends for his team-mate with a brilliant double save. The Czech, brought on as Romain Lukaku was sacrificed, parried Baines' penalty and then blocked the left-back's second attempt before Cahill headed wide.
Despite Cech's heroics, the tide had turned and Everton's pressure finally paid off as they equalised with seven minutes remaining when Saha met a cross from substitute Seamus Coleman with a perfect header at the near post. Cech was well beaten, as he was moments later when Drenthe flashed a shot across the face of goal.
The break allowed Chelsea to regroup and the numbers were evened up when Drenthe was dismissed for a second bookable offence after sending Ryan Bertrand sprawling. Anelka's misery continued as his fierce shot struck Baines on the line, hit the post and rebounded to safety, but Chelsea were not to be denied when Sturridge netted the winner five minutes from the end.