London Welsh's hopes of reaching the Amlin Challenge Cup quarter-finals have been boosted after Grenoble admitted fielding an ineligible player in their Pool Five encounter last Friday.
Grenoble won the game 20-9, but London Welsh have now been awarded a 28-0 victory and five match points.
It means London Welsh move from third to second in the pool, five points behind group leaders Stade Francais.
Grenoble were deducted four match points for fielding Lotu Taukeiaho.
The French club was also fined 10,000 Euros (£8,120).
Grenoble have the right to appeal against the decision. The two clubs meet in the return fixture at Oxford's Kassam Stadium on Saturday.