Former Swire Shipping Fijian Drua player Vinaya Habosi scored his first try for the season to help his Racing 92 side edge Castres 34-30 in the Top 14 competition this morning.
The Top 14 leaders ran in five tries.
Fellow Fijian winger Wame Naituvi, full-back Henry Arundell, and hooker Camille Chat scored a try each.
A penalty try was also awarded to Racing 92. Meanwhile, La Rochelle followed up their 29-8 win over defending Top 14 champions Toulouse last weekend with a 29-20 victory at Pau for the first away win of the season.
Toulouse was the biggest winner in the Top 14 this morning, pulling off a 45-0 against Lyon.
With seven tries, including the first of the season from Antoine Dupont and a double from Thomas Ramos, the reigning French champions put in an impressive performance ahead of their Champions Cup trip to Ulster.