Cesc Fabregas scored an extra-time brace as Chelsea came from two goals down to secure a 4-2 victory against 10-man Leicester City to advance to the fourth round of the EFL Cup.
The Blues found themselves two behind inside 34 minutes following Shinji Okazaki's early double, but goals either side of half-time from Gary Cahill and Cesar Azpilicueta soon brought them level.
Leicester's chances of victory were dealt a serious blow after they saw Marcin Wasilewski sent off just before the end of the 90 minutes, before Fabregas then struck twice inside two minutes in extra-time to seal Chelsea's progression.
It was Chelsea who had the ball in the back of the net first within just five minutes through Pedro, only for the goal to be disallowed with the Spaniard deemed to be offside as he latched onto a David Luiz pass.
Leicester did, however, find themselves ahead in the 17th minute with Okazaki arriving at the far post to head home from close range after Chelsea had failed to deal with a cross into the box. Azpilicueta did his best to clear the bouncing ball away, but was just unable to get to Okazaki's effort before it crossed the line.
Chelsea had a good chance to level proceedings soon after when Pedro picked out Michy Batshuayi at the far post, but the Belgium international was only able to send his header wide of the target.
And Okazaki then grabbed his and Leicester's second of the evening, this time getting on the end of Andy King's ball, before squeezing a strike past Asmir Begovic with Azpilicueta again failing to clear off the line despite his best efforts.
It could have been three shortly before the break with Demarai Gray letting rip with a strike from the edge of the area that sailed wide.
There was still time in the first half for Cahill to pull one back for Chelsea deep into stoppage time, losing his marker from a corner before heading past Ron-Robert Zieler as Danny Drinkwater just failed in his attempts to clear off the line.
And just a few minutes after the restart Chelsea were level as Azpilicueta volleyed home into the top corner from the edge of the box in style, leaving Zieler with no chance.
With the game having turned into a cagey affair, Chelsea opted to bring on Diego Costa to try and find a winner -- and just a few minutes after his arrival, the striker was presented with a great chance but was only able to fire wide after being played in on goal.
Batshuayi also came close to edging the Blues ahead as they looked to turn the screw, taking aim from the edge of the area with a fine strike which brought a brilliant fingertip save out of Zieler.
It was then Begovic's turn to produce a fine stop down the other end as he got an arm to Ahmed Musa's effort to turn it wide, before Andy King then wasted an excellence chance from the resulting corner, heading over from close range.
Another chance fell Costa's way as time began to tick down at the King Power Stadium, but he was unable to find a way past Zieler, who again kept out the Spain international at his near post a few moments later.
Luiz, Victor Moses and Costa all fired off target as Chelsea did their best to find a third in the dying minutes, while there was still time for Leicester's Wasilewski to receive his marching orders after a late challenge on Costa before the full-time whistle eventually sounded.
But Chelsea did not have to wait long to find the back of the net once extra-time got under way, with Fabregas rifling home after meeting Eden Hazard's backheel.
And the midfielder was at it again just two minutes later, firing into the roof of the net after Leicester had failed to deal with the danger inside their box to move the Blues into the fourth round.