Clermont Auvergne moved back to the top of the Top 14 table thanks to a thumping 40-16 victory at Brive on Sunday.
Toulon had unseated Clermont with victory in Mike Ford's first game in charge on Saturday, but Franck Azema's men ran in four tries to open up a five-point lead at the summit.
The damage was done in the first half, when Patricio Fernandez, Charlie Cassang and Noa Nakaitaci touched down to help Clermont to a 27-9 lead at the interval.
Fernandez's kicking form carried into the second half and the Clermont number 10 added a second try to end the match with 25 points to his name.
Brive did register a try of their own through Lucas Pointud, but there was no way back for the hosts, who sit 10th.
Castres climbed above Brive with their 33-27 triumph against Bordeaux Begles at Stade Pierre-Antoine.
The hosts rode the momentum of their impressive European Champions Cup victory over Northampton Saints into a strong start, with Benjamin Urdapilleta's kicking central to his team's success – the fly-half ending the match with 18 points.