PREVIEW: Favourites looking for redemption
Defending champions Racing failed to score a try in their 15-9 defeat by Raphael Ibanez's Bordeaux-Begles, whereas Diego Dominguez saw his first game in charge of Toulon end in a 23-28 defeat against promoted Bayonne.
Stade Francais and Toulouse both managed victories in their opening matches along with Castres, whilst Clermont had to make for with a draw against La Rochelle.
Racing faced a rude awakening last week against Bordeaux-Begles, looking out of shape and struggling with the high tempo of the match.
"We're disappointed by the result because we wanted to win. Like we told the players at the end of the game, the holidays are over and the new season has started," said Racing coach Laurent Labit.
"We were inconsistent, gave away too many penalties and suffered when we had possession."
The six-time French champions will now face promoted side Lyon at home for the first time. Pierre Mignoni's men managed a draw against Brive in their opening match.
Toulon were left shocked by an impressive Bayonne, who were making their return to the Top 14, as they suffered an opening day loss on a weekend when no team won away from home.
Mourad Boudjellal's side was guilty of poor discipline, conceded two tries and had Springbok flank Juan Smith sent to the bin for a dangerous tackle that prompted new coach Dominguez to say he was "annoyed".
"We did not deserve to win," Dominguez said.
"The players made too many mistakes, there were too many lost balls. I'm annoyed because that was a game we could have won by being smart."
Last year's runners-up now travel to Pau who suffered a 28-11 defeat by Castres.
With the front-runners for the title slumping to opening day losses, Stade Francais and Toulouse grasped the opportunity to put some early pressure on their rivals.
Gonzalo Quesada's Parisians stormed to the biggest victory of the opening day with a 54-20 win over rivals Grenoble. Ugo Mola's men defeated Montpellier 20-12 in a southern France derby.
Toulouse, who are looking for a first Top 14 title since 2012, will now play against Bordeaux whom they didn't manage to beat last season, while Sergio Parisse-led Stade travel to Brive.
Round Two fixtures (all times GMT)
Saturday, August 27:
Pau v Toulon (13.45)
Grenoble v La Rochelle (17.30)
Racing 92 v Lyon (17.30)
Bayonne v Castres (17.30)
Brive v Paris (17.30)
Toulouse v Bordeaux-Begles (19.45 GMT)
Sunday, August 28:
Montpellier v Clermont (1515 GMT)