Jason Denayer's first goal for Lyon fired them up to second following a 1-0 win over St Etienne.
But they had to survive the last 20 minutes with 10 men following a red card for Rafael.
Lyon, beaten just once at home this season, almost took a 10th-minute lead but Nabil Fekir headed Ferland Mendy's cross wide.
Yet St Etienne created a host of first-half chances with Anthony Lopes saving from Lois Diony and Mathieu Debuchy while Remy Cabella and Neven Subotic missed the target.
After the break Lyon's Maxwel Cornet fired over the crossbar and Moussa Dembele shot narrowly wide after he was set up by Memphis Depay.
And their pressure told in the 62nd minute when Denayer rose highest to power a downward header home from Depay's corner.
However, eight minutes later the hosts were reduced to 10 men when Rafael saw red for a foul on Yann M'Vila.
Timothee Kolodziejczak, Cabella and Yannis Salibur had chances to equalise but they could hit the target.