La Rochelle scored a last-minute try to snatch a 32-29 bonus-point win over Toulon in the French Top 14, while Clermont lost 31-10 to Castres.
Toulon, who face Clermont in the European Champions Cup final in a week's time, fielded a weakened starting XV against La Rochelle.
In a frantic first half, La Rochelle outscored their visitors three tries to two for a 22-20 advantage at the interval.
Toulon’s Frédéric Michalak booted three penalties in the second half, while Peter Grant kicked one for La Rochelle, bringing the score to 29-25 in favour of the visitors.
But in a dramatic finish, centre Malietoa Hingano went over in the 80th minute to secure a surprise victory for the hosts.
Meanwhile, winger Remy Grosso’s hat-trick led Castres to a shock triumph over Clermont. The hosts, who were in the relegation zone before the match, delivered a stunning performance to record their third successive win.
In other Top 14 matches, Scott Spedding scored a hat-trick to guide Bayonne to a 42-33 win over Grenoble in a thrilling encounter, Oyonnax edged Racing Métro 21-16, Brive defeated Montpellier 15-10 and Bordeaux claimed a 37-22 away win over Lyon.
In Friday’s only match, Toulouse beat Stade Français 21-12 in Paris, to replace them in third position on the log.
Round 23 results:
La Rochelle 32 Toulon 29
Castres 31 Clermont 10
Bayonne 42 Grenoble 33
Oyonnax 21 Racing Métro 16
Brive 15 Montpellier 10
Bordeaux 37 Lyon 22
Stade Français 12 Toulouse 21
Photo: Xavier Leoty/AFP Photo