Oyonnax pulled off a shock 11-10 victory over title-contenders Clermont at the Stade Marcel Michelin on Saturday.
In a low-scoring contest, Clermont looked to have done enough to claim victory, but a late penalty by Oyonnax flyhalf Benjamin Urdapilleta ended Clermont's 12-match winning streak at home.
The hosts, who changed their entire starting XV from the side that thrashed the Northampton Saints last week, scored the opening try through No 8 Peceli Yato and Brock James converted.
Oyonnax replied with a penalty on the stroke of half-time, before wing Soane Tonga'uiha dotted down after the break, as they led 7-8. With nine minutes left, James added a penalty goal and from then on Clermont tried to defend their slender two-point lead. But Urdapilleta had the final say when he nailed a last-gasp penalty kick to give his side a surprise win on the road.
In other Top 14 matches, Stade Français drew 19-19 away to La Rochelle, Racing Métro had to settle for a 24-24 draw with Montpellier after Johan Goosen missed a late kick at goal, Toulouse beat Bayonne 20-17, Brive claimed a 22-20 win over Lyon, Grenoble lost 35-24 at home to Toulon, and Castres moved out of the relegation zone with a 22-20 victory against Bordeaux-Bègles.
Round 22 results:
Clermont 10 Oyonnax 11
Stade Français 19 La Rochelle 19
Racing Métro 24 Montpellier 24
Toulouse 20 Bayonne 17
Brive 22 Lyon 20
Grenoble 24 Toulon 35
Castres 22 Bordeaux-Bègles 20
Photo: Thierry Zoccolan/Getty Images
