Chelsea boasted three changes from the weekend’s 2-0 Premier League win against Brighton as N’Golo Kante returned to replace Ross Barkley in midfield, while Kurt Zouma came in for Andreas Christensen at centre-back and 19-year-old Reece James made his Champions League debut.
Hosts Lille had former Chelsea striker Loic Remy and ex-Swansea loan midfielder Renato Sanches on the bench from the start.
Chelsea enjoyed the better of a scrappy opening to the game with Tammy Abraham and Mason Mount having half-chances to put their side in front.
But, on 20 minutes, Kepa Arrizabalaga had to race out of his area to head the ball clear when Victor Osimhen got the better of Zouma and looked set to have a free run at goal.
That intervention from the Blues’ custodian was even more significant when his side went up-field and took the lead a minute later.
Fikayo Tomori lifted the ball into the area and picked out Abraham with the birthday boy finishing past Mike Maignan into the far corner of the net.
Kepa rescued the Blues again moments later as he tipped Luiz Araujo’s left-foot effort wide of the far corner. But he couldn’t do much about Lille’s equaliser on 33 minutes when Osimhen was given too much space as he powered in a header from a Jonathan Bamba corner.
Chelsea recovered from that setback and were unfortunate not be back in front before the break when Marcos Alonso flashed a header just over the crossbar, before Jorginho rattled the post in stoppage time.
Kepa prevented Lille from taking the lead on 52 minutes when he produced a super finger-tip save to prevent Benjamin Andre’s header from creeping inside his near post.
Both sides continued to press for a second goal and it was Mount who went close on 73 minutes when he was set up by Willian but his scuffed effort was tipped away by Maignan.
Chelsea did get their second of the night to re-take the lead on 77 minutes when Willian celebrated his 300th appearance for the Blues when Callum Hudson-Odoi picked him out on the right side of the box and he fired past Maignan.
The night ended on a sour note for Willian as he had to limp off with a possible hamstring injury five minutes from time.
The win moves Chelsea up to second in the group behind leaders Ajax, who won 3-0 away at Valencia.