A long-range strike by Oscar helped Chelsea edge past Bolton 2-1 at Stamford Bridge as they reached the fourth round of the Capital One Cup.
The home side broke the deadlock after 25 minutes when defender Kurt Zouma, making his first competitive start following his January move from Saint Etienne, stabbed the ball home from close range after Loic Remy had flicked the ball on in the area.
However, the visitors hit back within six minutes after a deep free-kick was headed in off the post by captain Matt Mills beyond captain Petr Cech's dive.
It denied the Czech goalkeeper a clean sheet and left the normally miserly Blues with one shutout in seven matches this season.
With Chelsea applying the pressure, they eventually broke Wanderers' resistance 10 minutes into the second half thanks to a low, skimming strike from 25 yards by Oscar.
Despite some late pressure from the Championship club, it was the Premier League leaders who advanced.
Andre Schurrle spurned a host of chances and Bolton goalkeeper Andrew Lonergan was in fine form to deny the hosts.
Bolton are opponents who come with some nostalgia for Chelsea, who made nine changes with only Cesar Azpilicueta and former Wanderer Gary Cahill retained from the side which draw at Manchester City.
Two goals from Frank Lampard at Bolton secured the 2-0 win which confirmed Chelsea's first championship in 50 years in 2005.
The Blues also won the League Cup nine years ago, in Jose Mourinho's first season in English football, and, as the first silverware on offer in the season, it can provide a boost at a crucial stage in the campaign.
The visitors have one win in eight Championship matches and made five changes from the side which lost at Wolves, including a debut for Chris Herd, a loan signing from Aston Villa, who visit Stamford Bridge on Saturday.
Chelsea's fringe stars were told to seize their opportunity to impress and they could have put the game out of sight in the opening quarter.
World Cup winner Schurrle had a wickedly inswinging free-kick clawed behind by Lonergan before his weak header from Mohamed Salah's cross.
Lonergan saved from Oscar, Salah prodded wide, Remy headed off target and Schurrle had a free-kick tipped on to the bar by Lonergan as Chelsea bombarded the visiting goal.
Schurrle, again, went close, before Chelsea took the lead from a corner, when Cahill's header was blocked and Remy headed the ball back into the six-yard box, where Zouma pounced.
Schurrle found the top tier of the Shed End from Remy's cross and Salah curled wide from Oscar's pass before Chelsea were made to pay for their lack of precision.
Troy Deeney's deep free-kick from the right found Mills on the edge of the hosts' box.
Mourinho would have been concerned to see a journeyman defender at his ninth club climb highest to convert from 16 yards, the ball glancing off the post and in.
Schurrle again fired off target, Nathan Ake was denied from 25 yards by Lonergan and, after the restart, Oscar had a header saved.
Even the less than prolific John Obi Mikel tried his luck, shooting straight at the goalkeeper, before Lonergan was beaten for a second time.
A direct Remy run ended with a blocked shot, but the rebound fell to Oscar, who emphatically drilled in with the Bolton defence backing off.
Schurrle headed over and Oscar curled a free-kick narrowly over before Remy was denied by Lonergan after neat build-up play by Salah and Schurrle, who then again curled wide.
The German forward fired a free-kick off target after Didier Drogba's introduction.
Eden Hazard was introduced 11 minutes from time in a further indication that Mourinho did not want extra-time and of the Portuguese's concern at his side's wasteful evening.
Schurrle came closest when he turned Dean Moxey inside and out before firing a shot which Lonergan claimed, but only after palming it on to the post.
Cech was called upon to save from Bolton substitute Lee Chung-yong five minutes from time before Drogba cleared from a corner as Wanderers pressed to force extra-time, but, to the relief of much of Stamford Bridge, the hosts held on.