The Brazil striker fired home with a superb free kick after Yuri Berchiche had opened the scoring on the stroke of halftime, with Giovani Lo Celso sealing a straightforward victory in the closing stages.
The win put PSG on 62 points from 24 games with second-placed Olympique de Marseille, who hammered Metz 6-3 away on Friday, on 51.
Lille are 17th on 25 points, one point above safety.
PSG went ahead in the 45th minute when Berchiche netted with a low shot after the Lille defence had failed to clear Edinson Cavani's cross.
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Neymar, who was doubtful after taking a knock earlier this week, doubled the tally with a 17-metre free kick into the top corner.
Lo Celso then scored his first Ligue 1 goal with a fine lob over Mike Maignan in the 87th.
(Reporting by Julien Pretot; Editing by Clare Fallon)
