Valentin Eysseric's first goal of the season dealt a blow to Lyon's title hopes as 10-man Nice snatched a late 2-1 win.
PSG went top of Ligue 1 for the first time this season after title-rivals Lyon lost 2-1 at home to 10-man Nice on Saturday.
Monaco were 3-0 victors at home to nine-man Bastia in Ligue 1 on Friday night, while Guingamp won 2-1 at Nice.
Nice's worrying slide towards the foot of Ligue 1 continued on Friday night as they went down 2-1 at home to Guingamp.
Bastia claimed a 2-1 comeback win over nine-man Nice in an ill-tempered match at Stade Armand-Cesari-Furiani.
Montpellier continued their fine form to move into the top six of Ligue 1 with a 2-1 home victory over Nice.
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