Chaz Davies was taken to hospital after being run-over by Jonathan Rea in a nasty crash in the opening World Superbikes race in Italy.
The Knighton-born rider crashed just a couple of laps from the finish while leading the reigning two-time champ.
Rea could not avoid running over Davies and also crashed at the right-hander but was able to pick himself up to finish third.
Davies was quickly to his feet after the high-speed incident but was then stretchered off the Misano track.
Rea stopped on his warm-down lap to check on Davies who was taken to the circuit’s medical centre before being transferred to hospital in Rimini having struggled with his breathing.
The 30-year-old had a scan which diagnosed he had broken a bone in his lower back as well as injured his left thumb.
Davies will miss Sunday’s second race and will rest before facing a fitness test ahead of the next round at Laguna Seca in California next month.
Rea said: “I am so sorry I hit Chaz, but I just had nowhere to go.
“I was thinking about attacking at the last corner but he made a mistake and I just went over him.
“I’ve lost the race, but right now my only thoughts are with Chaz and I hope he is okay.”
Davies’ aruba.it-Racing team-mate Marco Melandri also crashed on the final lap allowing Tom Sykes to inherit a fortunate win.
Ernesto Marinelli, the team’s Superbike Project Director, said: “The end of today’s race leaves a bitter taste in our mouth.
“Chaz and Marco rode a memorable race, both showing they could win, but they crashed out during the last lap. Marco will have another go at it tomorrow, while we’re deeply saddened by what happened to Chaz.
“He will now observe a rest period, but he has a strong character and I’m sure he’ll tackle it with the same mettle he’s racing with.”