Michael Fatialofa is in intensive care and the Worcester Warriors lock will have surgery to ease the pressure on his spinal cord.
Stade Francais came into the Clasico sitting bottom of the Top 14, yet they pulled off a thrilling win in Paris as Toulouse wilted.
Worcester Warriors lock Michael Fatialofa had to be carried off on a stretcher versus Saracens and he remains under observation in hospital.
He may have been granted an early release by Toulon, but Rhys Webb will not play for them again if owner Bernard Lemaitre has his way.
Sam Hill and Gareth Steenson starred for Exeter in their win over London Irish, while Taqele Naiyaravoro was the hero for Northampton.
With hazardous air quality in Canberra, the Brumbies have temporarily relocated to Newcastle.
High-flying pair Lyon and Bordeaux Begles celebrated contrasting victories in Top 14 action on Saturday.
Ospreys were boosted by George North's return but still could not see off Dragons in Pro14.
Five tries in each half saw Premiership basement side Saracens make light work of thumping Worcester Warriors on Saturday.
Ulster maintained their unbeaten home record in the Pro14 with an emphatic win over Munster, who slipped off the top of Conference B.