Pau moved above Racing 92 into first place in the Top 14 on Sunday after grinding out a 13-9 home victory over reigning champions Toulouse.
The hosts, who have won four straight matches after losing their opening game of the season, scored the only try of the contest in the 16th minute through Australian Reece Hewat.
Joe Simmonds converted that score and also kicked a penalty to give Pau a 10-9 halftime advantage, with France star Melvyn Jaminet kicking three penalties for Toulouse.
Simmonds added another penalty in the 62nd minute to give Pau some breathing space, and they held on for their third successive home win against Toulouse.
Racing are behind Pau on head-to-head record in second place after edging out Lyon 22-20 on Saturday.
French Top 14 result:
Pau 13 Toulouse 9
Saturday
Oyonnax 19 La Rochelle 17
Perpignan 26 Toulon 22
Bordeaux-Begles 26 Montpellier 13
Clermont 46 Bayonne 14
Stade Francais 39 Castres 16
Racing92 22 Lyon 20