Clermont Auvergne secured its fourth successive Top 14 victory as the boot of former Scotland captain Greig Laidlaw helped it overcome Pau 27-23.
Exeter Chiefs and Saracens maintained their unbeaten starts to the new Premiership season to make it three wins from three.
Bath was denied victory over local rival Gloucester by a familiar face, while Billy Vunipola marked his return to action with a try for Saracens on a busy day in the Premiership.
Danny Cipriani produced a virtuoso display on his Gloucester debut to help his new team record a 27-16 Premiership win over Northampton Saints.
Bristol Bears made a fine start to life back in the Premiership with a 17-10 success over local rival Bath at Ashton Gate.
Jacques van Rooyen has left Super Rugby runner-up Lions to join Premiership side Bath.
Sergio Aguero struck twice, while Vincent Kompany, Fernandinho and Gabriel Jesus were also on target as Manchester City thumped Watford 5-0.