Reece Burke gave Town the lead after only two minutes, heading in from Luke Berry’s corner. Chelsea equalised through Saul, before Harry Cornick put Luton back in front before half-time.
But the Blues would progress in the competition with second half goals from Timo Werner and Romelu Lukaku.
Nathan Jones made a number of changes from Saturday’s win against Derby County. Dan Potts and Peter Kioso came into the Hatters’ defence, with Berry, Gabe Osho and Carlos Mendes Gomes in the Town midfield.
Town got off to the perfect start, scoring within the opening two minutes. Berry’s corner was perfect for Burke, whose header left Kepa Arrizabalaga with no chance in the Chelsea goal.
The Hatters were forced into a change early, with Jed Steer unable to continue. Harry Isted replaced the Aston Villa loanee, coming on for his third senior appearance for Luton.
Chelsea’s first effort on goal came through Saul. After a cross from Mason Mount, the Spaniard’s header did not trouble Isted who made an easy save.
Dan Potts saw a header of his own saved by Kepa, after good work from a short throw-in from Town.
But Thomas Tuchel’s side would be level just before the half-hour mark. Werner cut inside the Hatters’ defence, and the ball fell into the path of Saul who curled the ball beyond Isted.
The 'keeper was then forced into a number of saves in quick succession. First, he saved from Saul, before tipping a venomous effort from Kenedy over the crossbar.
Lukaku was next to threaten for Chelsea, firing in from Mount’s cutback. Isted made another fantastic save to deny the Belgian international.
The Hatters went back in front before half-time. After being played through by Carlos Mendes Gomes, Cornick ran through one-on-one and calmly slotted beyond Kepa.
Town would go into the break 2-1 up against the World Champions, after a breathless first half at the Kenny.
Chelsea would register the first chance of the second half. From Kenedy’s corner, Saul attempted an ambitious flick at the near post, but it was well over Isted’s crossbar.
The Blues would make two changes on the hour mark, with Christian Pulisic and Harvey Vale introduced for Kenedy and Callum Hudson-Odoi.
Town would also make two changes of their own, with goalscorer Cornick being replaced by Cameron Jerome. Allan Campbell came on for Berry.
Chelsea would equalise through Werner. Ruben Loftus-Cheek found the German international with a ball forward, and he finished beyond Isted.
Danny Hylton was brought on for Admiral Muskwe, and Robert Snodgrass was given his Hatters debut as he replaced Mendes Gomes.
Tuchel made a further substitution for Chelsea, with Reece James coming on for Jorginho.
Chelsea would take the lead for the first time in the game through Lukaku. Werner’s ball across goal was perfect for the £97.5m man, who slid the ball into the back of the net.
After a fantastic performance and leading twice against the world champions, it wasn’t to be for the Hatters who fell just short.
Goals:
Town: Burke (2’), Cornick (40’)
Chelsea: Saul (27’), Werner (68’), Lukaku (78’)
Att: 10,140 (1,570 away)
