The result sees Unai Emery's PSG climb to second on 23 points behind Ligue 1 leaders Nice
The result sees Unai Emery's PSG climb to second on 23 points behind Ligue 1 leaders Nice who have 26 ahead of hosting Nantes on Sunday. Third placed Monaco, on 22 points, travel to St Etienne on Saturday.
It was a real moment of magic from 29-year-old Cavani as the Uruguayan controlled Angel di Maria's pass with his chest, swivelled and unleashed an unstoppable shot for his 10th league goal of the campaign on 64 minutes.
The first half was marked by a duel between di Maria and Lille's Nigerian international goalkeeper Victor Enyeama, who saved twice from close range.
The Argentine also had a 22nd-minute 'goal' ruled out for hand ball.
Struggling in Ligue 1, Frederic Antonetti's Lille were no pushovers and were organised from start to finish.
They may easily have scored on three occasions, none more so than when Younousse Sankhare missed from point blank range on 82 minutes when the ball came to him from an Eder cross right on the goalline.
PSG captain Thiago Silva was forced into a panicked overhead clearance from his own six yard box shortly afterwards.