Oyonnax stunned Clermont Auvergne at the Stade Marcel-Michelin and Toulon capitalised by winning away in Grenoble.
Julien Bonnaire has signed a two-year contract with Lyon, while Irish centre Eamonn Sheridan has joined US Oyonnax.
Rupert Cox shares his highlights from the week's rugby action in his round-up blog.
Toulon once again find themselves at the top of the French domestic league thanks to a five-try win over Brive.
Bordeaux came back from an 11-point deficit to defeat Toulon 28-23 in the Top 14 at the Stade Chaban Delmas.
Lyon restored their two-point lead at the top of Ligue 1 after Clinton Njie's late goal salvaged a 1-1 draw at Lorient.
Clermont and Stade Francais both suffered losses in the Top 14, leaving them locked together with new leaders Toulon.
Team news for Sunday's European Rugby Challenge Cup Pool 4 meeting of London Welsh and Lyon at the Kassam Stadium.
More of the games that matter on Sky Sports
Watch the action with a Day or Week Pass
Buy tickets for Sale and Barbarians v Argentina.
For all the latest news, features and videos
We've a host of top class rugby union action