Uncapped English fly-half Joe Simmonds slotted 15 points as surprise packages Pau beat Stade Francais 30-6 on Saturday to take the lead in the French Top 14.
Pau, usually involved in the relegation scrap, go above Toulon with their sixth win out of eight games this season.
Former Exeter Chiefs playmaker Simmonds, 26, keeps his place as the league’s top points scorer with a fine display from the tee.
Much-changed Stade Francais are third in the table with their only points of the game coming from Joris Segonds’ penalty and drop goal.
Elsewhere, controversial former French rugby federation president and ex-France head coach Bernard Laporte lost his first game as Montpellier director of rugby with a 26-21 defeat to promoted Oyonnax.
In December, former sports minister Laporte was handed a two-year suspended prison sentence for his financial dealings with Montpellier owner Mohed Altrad.
He was also banned from holding any rugby post for two years, but that is on hold pending his appeal.
Former Ireland fly-half Paddy Jackson scored a try, a conversion, a penalty and a drop goal as Lyon beat Bayonne 42-29 for just their third success of the season.
In 2018, Jackson and former Ulster teammate Stuart Olding were found not guilty of raping a woman in 2016.
France winger Damian Penaud crossed four times as Bordeaux-Begles hammered Perpignan 46-22, becoming the first player to score as many tries in a Top 14 game since 2018.
Earlier, Fiji winger Setariki Tuicuvu scored twice as Toulon easily overcame Castres 41-19 to temporarily move to the summit of the table.
His fellow winger Gael Drean, who was playing in the fifth tier of French rugby two years ago, also crossed on two occasions for 14-man Toulon after centre Jeremy Sinzelle was sent off early in the second half.
A minute’s silence will be held before each game at all levels of the sport in France this weekend after a 16-year-old player named Thomas was killed during a night out last week.
Later on Saturday, France captain Antoine Dupont starts as champions Toulouse host Clermont, who also have a former lower-league player in their line-up with youngster Robin Couly at hooker, who was at a sixth-tier club last season.
On Sunday, South Africa’s two-time World Cup winning captain Siya Kolisi will make Racing 92 debut against Ronan O’Gara’s La Rochelle.
