Two first-half tries from Henry Chavancy helped Racing go into a 23-9 lead at half-time and a Jonathan Wisniewski try soon after the restart pushed them further ahead.
Virimi Vakatawa then went over to put Racing out of sight and though Rudi Coetzee and Gavin Hume got tries back for the visitors, Thomas Bianchin padded the lead and earned Racing a bonus point with a try five minutes from time.
Racing are now a point clear of
In another upset
A late penalty from Valentin Courrent earned