Remco Evenepoel has crashed and fallen several metres off a bridge during the Il Lombardia race.
The Deceuninck-Quick Step rider was part of a leading group who were descending off the Colma di Sormano – the highest climb on the race.
The 20-year-old was lying around fourth in the group when he struck the wall of a bridge before somersaulting on to his back and over the edge.
Evenepoel was attended to by paramedics and taken to hospital.
The Belgian is one of the most promising prospects in road cycling, winning the Tour of Poland and the Volta a Burgos already this year.
The one-day ‘monument’ race from Bergamo to Como was won by Jakob Fuglsang of Astana after breaking away from Jumbo-Visma’s George Bennett – himself on good form after winning the Gran Piemont one-day race in Italy last week.
They were in a breakaway with multiple Grand Tour winner Vincenzo Nibali and last year’s Il Lombardia victor Bauke Mollema, both of Trek-Segafredo.
In another bizarre twist at the end of the race Bora-Hansgrohe’s Max Schachmann was struck by a car which somehow entered the closed roads and cut across the German Paris-Nice winner as it attempted to park.
Quick Step’s second horrifying injury in a week
The Tour of Poland was also the race where Evenepoel’s team-mate Fabio Jakobsen last week suffered a huge crash in a bunch sprint on the first stage.
Jakobsen was hospitalised and put into an induced coma as well as having plastic surgery to his face.
The crash was caused when Jumbo-Visma’s Dylan Groenewegen leaned toward Jakobsen, causing him to be pitched into barriers which broke and saw the sprinter strike a post and a spectator, who also needed hospital treatment.
It prompted an angry reaction, leading Jakobsen’s team boss to call for Groenewegen to be jailed.
Jakobsen has since been transferred to hospital in his native Netherlands to continue his recovery.