Swiss ace Marc Hirschi followed up on his stage win at this year's Tour de France by seeing off several senior rivals on the vertiginous Mur de Huy climb to win the Fleche Wallonne cycling classic on Wednesday.

The 22-year-old Sunweb rider was one of a new generation of cyclists who lit up the 2020 Tour and this one-day classic victory confirms his arrival in the sport's elite after he placed third in the world championships at the weekend.

Frenchman Benoit Cosnefroy was second and former hockey player Canada's Michael Woods was third.

Originally scheduled for mid-April, this long 202km run through the tolling and damp Ardennes countryside is a major date on the one-day calendar.

Rescheduled after the pandemic it is the precursor to Belgium's biggest race, the Liege-Bastogne-Liege on Sunday. 

Hirschi said his win came as a surprise as he had been feeling off colour.

"I didn't feel that good today but I just said lets just do the best you can," said the bearded youngster.

"Its steep, you can't go to early, it needs mental strength," he explained of the narrow road on the Mur de Huey climb.

"It  was perfect for us there were just four of us up front at the end and it was just a question of the legs on the last climb," said Hirschi, who is managed by Swiss cycling legend Fabian Cancellara.

Fresh from her exploits claiming both world road race titles at the weekend, Dutch cyclist Anna van der Breggen raised her arms in victory at the women's 124km La Fleche Wallonne earlier Wednesday.

Van der Breggen attacked over the final 100m of the short, steep Mur de Huy climb to finish ahead of Denmark's Cecilie Uttrup Ludwig and another Dutch woman Demi Vollering at the summit.