Simon Zebo scored his first try of the season to secure the bonus point for Racing 92 before the break at the Paris La Défense Arena.
He cantered home from 10 metres after a pop pass from scrum-half Maxime Machenaud to get their fourth try and send them in 26-5 ahead at the break as they wrapped up the anticipated victory over an Ospreys side who rallied late on to punish poor defending.
The victory leaves the Parisians in control of Pool 4 heading into the final two rounds regardless of what happens between Saracens and Munster today.
Last week, Ospreys, who have only won once in 11 outings this season, lost full-back Dan Evans to a red card after just 38 seconds.
This time round there were only 38 seconds gone when Machenaud burst over for a try but there was relief for Ospreys when it was called back for a knock-on.
Good Ospreys pressure yielded a try for Luke Morgan for the Welsh to hit the front after eight minutes.
But notions of an upset disappeared as Ospreys imploded and conceded two tries in four minutes.
Ospreys out-half Marty McKenzie was dispossessed in midfield by tighthead Cedate Gomes Sa and the turnover ended with Racing academy product Louis Dupichot scoring down the right.
McKenzie’s night got worse when a pass from the former New Zealand U20 out-half was intercepted by Juan Imhoff and the former Argentina winger sauntered home.
He got his ninth of the season when an inside pass from Fijian out-half Ben Volavola put Dupichot away and in turn he set up his other winger Imhoff to make it 19-5 when Machenaud converted.
Then came Zebo’s try to seal the bonus point before the interval, and really all that remained to be decided was the margin of victory and, in particular, how many more tries Racing might score.
Ospreys, down to the bare bones after having to borrow two props from Scarlets during the week, battled away but the Racing pressure inevitably told and replacement tighthead Georges-Henri Colombe scored shortly after coming after Zebo was stopped short.
No.8 Yoan Tanga got their sixth try to make it 40-5 after 53 minutes but it was Ospreys who dominated the final quarter, with Lesley Klim slipping past Zebo to score and they picked up their first point of the campaign when Luke Price got their fourth, while more sloppy defending allowed Klim get his second of the night.
Tries: J Imhoff (2), L Dupichot, S Zebo, G Colombe, Y Tanga. Cons: M Machenaud (5).
Tries: L Klim (2), L Morgan, L Price, S Venter. Con: L Price
S Zebo; L Dupichot, V Vakatawa, H Chavancy, J Imhoff; B Volavola, M Machenaud; E Ben Arous, T Baubigny, C Gomes Sa; D Ryan, B Palu; F Sanconnie, B Chouzenoux, Y Tanga.
H Kolinger for Ben Arous (48), G Colombe for Gomes Sa (48), O Klemenczak for Vakatawa (50), D Bird for Ryan (50), A Gilbert for Machenaud (54), C Chat for Baubigny (62), J Joseph for Baubigny (62), F Russell for Chavancy (79).
C Evans; L Klim, T Thomas-Wheeler, K Williams, L Morgan; M McKenzie, S Venter; N Smith, S Otten, M Fia; A Beard, L Ashley; D Lydiate, S Cross, M Morris.
S Gardiner for Fia (47), L Price for McKenzie (48), T Williams for K Williams (48), R Fawcett for Smith (48), D Lake for Otten (51), G Volpi for Lydiate (58), A Davies for Evans (65), W Jones for Morris (70).
Luke Pearce (England).