Leaders Toulouse broke a Top 14 record as they stretched their unbeaten run to 12 games with a 28-9 win over Stade Francais in Paris.
Having seen Clermont Auvergne reduce their lead at the summit to a point following their 52-17 victory against Grenoble on Saturday, a Toulouse side depleted by international call-ups responded by restoring their six-point cushion with a four-try triumph over the capital club.
Gillian Galan and Lucas Tauzin went over in the first half to give the leaders a 12-9 advantage, with all of Stade Francais' points coming from Nicolas Sanchez penalties.
Two Zack Holmes penalties enhanced Toulouse's advantage and Piula Faasalele and Matthis Lebel crossed in the closing 10 minutes as Ugo Mola's side extended an undefeated Top 14 run that dates back to a September loss to Castres.
Bottom club Perpignan suffered their 17th loss out of 18 games as Toulon fought back from an early deficit to triumph 24-11.
Enzo Selponi's penalty and Jonathan Bousquet's try put Perpignan in charge only on, yet the visitors rallied through scores from Liam Messam and Josua Tuisova, with Bruce Devaux also crossing 14 minutes from time to seal a first away win of the campaign for Toulon.