Mathieu van der Poel took the Tour of Flanders honours on Sunday for the Dutch cross-code rider's first win in one of cycling's so-called 'Monuments'.
The race was overshadowed by world champion Julian Alaphilippe's heavy fall after colliding with a motorbike.
Van der Poel had slipped away from the peloton with his great Belgian rival Wout van Aert, who like him is a three-time cycle cross world champion, and Alaphilippe forming a three-man breakaway.
But Alaphilippe crashed out of contention, leaving the duo to fight it out in a pulsating finish.
"The world champion was taken to the hospital where the X-rays showed fractures on his right hand," said a statement by the French rider's Deceuninck Quick-Step team.
"Alaphilippe, who was making his last appearance of the season in Flanders, will be operated Monday morning."
Van der Poel emerged the winner in Audenarde 34 years after his father Adrie's name was added to the celebrated race's roll of honour.
In the run-up to the Antwerp start of the race, which was moved from its traditional slot in the cycling calendar due to the Covid-19 pandemic, all the signs were that this duo held the key.
When Alaphilippe broke away from the pack 40 kilometres from the finish only van der Poel went with him, Van Aert missing the move and as a result had to use up vital energy catching the two leaders on the cobblestones of Taaianberg.
That effort coming after a fall 100km out will have surely taken its toll in the thrilling wheel-to-wheel sprint for the line.
Van der Poel, the 25-year-old grandson of the late Raymond Poulidor who sealed his place in the French public's affections by coming second on the Tour de France three times but never winning it, added Flanders to last year's wins in the Amstel Gold classic and Tour of Britain.
For Alaphilippe, the crash capped a tumultuous October.
He won the Belgian semi-classic la Fleche Brabanconne for his first win in his world champion rainbow-coloured jersey.
That made up for his farcical finish at Liege-Bastigne-Liege a week earlier when he raised his arms in celebration too soon and was embarrassingly pipped on the line after he stopped pedalling.