The 299-kilometres one-day race had seen attention focus on pre-race favourites Julian Alaphilippe of France, defending champion Wout Van Aert of Belgium and Dutch star Mathieu van der Poel.

The trio remained in the lead group heading into the key final climbs, the Cirpress and Poggio.

World champion Alaphilippe attempted an attack on the Poggio as he sought a repeat of his 2019 triumph, with his expected rivals following closely.

The main group remained together on the climb, with Britain’s Tom Pidcock leading the race on the descent to the finish.

Stuyven took advantage of the focus on the favourites by launching an attack two kilometres from the line and the Belgian rider opened a gap to the group.

Denmark’s Søren Kragh Andersen bridged across the gap to join Stuyven as the race entered the final kilometre, but was unable to stay with the Trek-Segafredo rider as the sprint began.

Stuyven successfully held off the sprinters in the closing metres to triumph in 6 hours 38min and 6sec.

Caleb Ewan of Australia finished as the runner-up after ending on the same time as the winner.

Van Aert completed the top three, with the Jumbo-Visma rider missing out on becoming the first to win the race in consecutive years since Germany’s Erik Zabel achieved the feat in 2000 and 2001.

Slovakia’s Peter Sagan finished fourth, while Van der Poel was forced to settle for fifth.

"It was the hardest final meters of my career, but I’ve won other races in a similar way," said Stuyven.

"It’s one of my strengths, to stay out front if they give me the gap.

"Winning a Monument this way is really nice.

"It’s normal that pre-race favourites were designated, based on how those three were riding.

"If I had to go one against one of them, there was a big chance that they were stronger than me.

"I said in a lot of interviews that they’re strong and fast but that doesn’t mean I’m on the start line of a race to just finish fourth.

"That’s my approach to every race.

"If you believe in yourself, they’re not unbeatable, that’s the right mentality for winning."

The Tour of Flanders in Belgium, scheduled for April 4, will be the next of cycling’s monument races to be contested.

The International Cycling Union WorldTour season will continue with the Volta a Catalunya stage race, which will take place from March 22 to 28.

Italy will again be the focus of the cycling world tomorrow when the Trofeo Alfredo Binda-Comune di Cittiglio, a Women's WorldTour race, takes place in Lombardy.