Ronan O'Gara's La Rochelle were beaten 25-24 at Castres in the French Top 14 on Saturday a week after being knocked out of the Champions Cup quarterfinals.
The two-time Champions Cup winners were hammered by Leinster last Saturday but move up to fourth in the table thanks to the bonus point with four rounds of the French regular season to play.
Young winger Nathanael Hulleu crossed twice in eight minutes for the home side, who move up to sixth place, the final play-off spot, with their first win in five games.
Former New Zealand scrum-half Tawera Kerr-Barlow was missing for O'Gara's side after suffering a head knock against Leinster.
Despite Kerr-Barlow's absence La Rochelle led 14-13 at the break thanks to an impressive solo try from Samoa centre UJ Seuteni.
Hulleu's double in the final 15 minutes swung the game in Castres' favour as the 23-year-old took his try tally to nine for the season.
Toulouse are without Antoine Dupont later as they face Toulon at Marseille's Velodrome with the scrum-half again away with France's sevens set-up before this summer's Olympic Games.
League leaders Stade Francais host Bayonne while South Africa's two-time Rugby World Cup winner Siya Kolisi is missing with an ankle injury for Racing 92's trip to Oyonnax in the week he was named among Time magazine's 100 most influential people of 2024.
On Sunday, Bordeaux-Begles host Clermont a week on from their heartbreaking one-point Champions Cup loss to Harlequins.