Lyon's lead at the Top 14 summit was reduced to just one point as they were comprehensively beaten 33-8 by Montpellier on Saturday.
Ospreys were no match for Saracens on Saturday, while Exeter Chiefs were among the other European Champions Cup winners.
Racing 92, Northampton Saints and Connacht were all winners in Sunday's European Rugby Champions Cup action.
Wing Teddy Thomas put more pressure on Stade Francais coach Heyneke Meyer as Racing 92 came out on top in the Paris derby.
An early red card was decisive as Bordeaux-Begles suffered their second defeat of the Top 14 season.
It was another game and another win for Lyon in Top 14, where Castres were defeated by Toulouse on Saturday.
Racing 92 dominated the second half to beat Pau before La Rochelle were beaten by Toulon at Stade Mayol.
Despite seeing their try line breached for the first time this season, Lyon maintained a 100 per cent start to the season in the Top 14.
Toulon and Agen each won in the Top 14 on Sunday, with Racing 92 unable to complete a turnaround while Montpellier were outplayed.
Toulouse won the Top 14 last season but they have been beaten in each of their first two matches at the start of the 2019-20 campaign.