Bamba netted a goal in each half and set up a third for Nicolas Pepe as Lille cut Paris St Germain’s lead at the top of the table to five points, though they have played a game more.
It was a fourth win in five games for Lille, who were in the relegation mix last season, but have been rejuvenated under manager Christophe Galtier, who spent eight years at St Etienne before joining his new club in December.
Third-placed Montpellier were held to a 1-1 draw by bottom side Guingamp in a match in which both sides had players sent off in the first half.
Guingamp forward Marcus Thuram was red-carded seven minutes in after a referral to the Video Assistant Referee showed he had struck Montpellier defender Daniel Congre.
Andy Delort gave the visitors the lead, but they were also reduced to 10 players after two yellow cards in a matter of seconds for Florent Mollet, the first for a foul and the second for his sarcastic applause to referee Jeremy Stinat.
Nicolas Benezet equalised for Guingamp 20 minutes into the second period for what they will view as a good point in the circumstances.
South African striker Lebo Mothiba continued his good start at Strasbourg with a brace of first-half goals as they drew 2-2 at Angers, taking his tally to four in six appearances since his move from Lille.
But Romain Thomas scored a stoppage-time equaliser for the home side after Pierrick Capelle had pulled a goal back in the second period. Thomas Mangani also missed a penalty for Angers.
Saman Ghoddos scored the only goal as Amiens beat visiting Dijon 1-0 while Nimes and Reims drew 0-0. (Reporting by Nick Said, editing by Ed Osmond)