The French star was expected to be among the contenders for the 197.8 kilometre stage from Brest to Landerneau, with a late climb offering an opportunity to attack.

Alaphilippe attacked inside the final three kilometres of the race, with the Deceuninck-Quick-Step rider able to pull clear of his rivals to claim the stage win.

He became the first Frenchman to win the opening stage of the race for 20 years, with the 29-year-old celebrating the recent birth of his son by securing the yellow jersey.

Australia’s Michael Matthews finished as the runner-up at eight seconds down, with Slovenia’s Primož Roglič third on the same time.

Roglič earned one of the time bonuses on offer for a top three finish.

Alaphilippe leads the race by 12 seconds from Matthews, with last year’s runner-up Roglič a further two seconds behind.

Australia’s Jack Haig, The Netherlands’ Wilco Kelderman and defending champion Tadej Pogačar completed the top six on the stage.

The trio are among a group 18 seconds off the race lead, which also includes Britain’s Geraint Thomas.

The stage saw two dramatic crashes, with the first caused by a spectator inside the final 45 kilometres of racing.

The spectator held a banner facing television cameras as the peloton approached on a narrow road, with the sign knocking over Germany’s Tony Martin into the bunch.

Martin fell into Roglič, which set off a series of further crashes in the peloton.

Germany’s Jasha Sutterlin was the only rider forced to withdraw from the race as a result of the crash.

Reports in France have suggested organisers may seek to take legal action against the spectator for the incident, which former International Cycling Union President Brian Cookson described as "possibly the most stupid thing I have ever seen anyone do at a bike race".

The peloton regrouped only for a second major crash to occur in the closing 10 kilometres of the race.

A high speed crash on a descent impacted several riders, with Australia’s Richie Porte among the general classification riders to lose time in the incident.

Britain’s Chris Froome, returning to the race for the first time since a major crash threatened his career in 2019, appeared most impacted.

Froome ultimately returned to his bike and finished the stage.

Earlier in the day, the eighth edition of La Course, a one day women's race, took place over a 107.7km route from Brest to Landerneau.

Victory went to Demi Vollering of SD Worx, with the Dutch rider outsprinting Denmark's Cecile Uttrup Ludwig of FDJ Nouvelle-Aquitaine Futuroscope.

Vollering's compatriot Marianne Vos of Jumbo-Visma finished third.

Victory capped a special couple of months for Vollering following on from her victory in Liege-Bastogne-Liege.

This year's edition of La Course is set to be the last, with organisers announcing an eight-day women's Tour de France for next year, scheduled from July 24 to 31 2022.