Former Munster second row Dave Foley scored the crucial try in Pau’s 19-16 win away to Oyonnax.
The 29-year-old, who had just come on as a replacement, won the game with his touchdown seven minutes from time to hand the visitors a lead they would hold until the final whistle.
Paddy Butler started for Pau, who now sit just outside the Top 14 play-off places in seventh.
72' essai de @davidfoley5 transformé par Tom Taylor 16 à 19 #USOSP #TOP14 #EnVertEtContreTous pic.twitter.com/GwqBhABRZu
— Section Paloise (@SectionPaloise) October 7, 2017
In England, Donncha O’Callaghan and Peter Stringer are still searching for their first win of the Premiership season with Worcester.
The Warriors remain rooted to the bottom of the table after a 29-13 loss away to Bath, their sixth defeat in a row.
A red card for fly-half Freddie Burns in the 63rd minutes did not help their cause.
Lock O’Callaghan started the game but was replaced by Christian Scotland-Williamson nine minutes into the second half, while Stringer came on for Jonny Arr with 10 minutes to play.
The duo will hope for a change of fortunes when they host Brive in the Challenge Cup on Sunday.
Former Ulster lock Dan Tuohy started for Leicester as they recorded their fourth straight league victory with a 28-27 success over London Irish at the Madejski Stadium.
The 11-cap Ireland international is currently on loan with the Tigers from Bristol.
Dominic Ryan was not in the visitors’ match-day squad.
Marty Moore, meanwhile, started for Wasps and scored a try in 25th minute of their tie at Saracens.
The former Leinster prop’s touchdown only served as a consolation, however, as the European champions recorded a 38-19 victory.
Former Leinster centre Brendan Macken played the entire game for the visitors.
