UAE Team Emirates rider Alexander Kristoff won the first stage of the Tour de France, a 156-km ride around Nice on Saturday.
The veteran Norwegian sprinter takes the first yellow jersey at this year's race with world champion Mads Pedersen of Denmark second and Sunweb's Cees Bol was third.
After a large group crashed inside the final 3km, Kristoff, 33, surged home in a sprint also involving Ireland's Sam Bennett, who was fourth.
Ineos' defending champion Egan Bernal largely avoided the trouble and finished safely in the peloton.
Rain made the roads treacherous and led to several crashes, including French hopes Thibaut Pinot and Julian Alaphilippe, with Colombia's Astana captain Miguel Angel Lopez suffering a jaw-dropping downhill slide that saw him slam face-first into a traffic sign.
Colombian Nairo Quintana, twice a Tour runner-up, fell earlier while Pavel Sivakov, one of Bernal's key lieutenants, hit the ground twice.
Pre-stage favourites Bennett, Caleb Ewan and Giacomo Nizzolo also crashed on slippery roads as rain wreaked havoc during the stage.
But the day belonged to an emotional Kristoff. He said: "It's a yellow jersey. I always dreamt about wearing it. Now it is a dream coming true. You cannot dream of a better start. We did not expect to win the sprint but I felt really strong and coming to the line I thought I was going to win.
"The boys kept me safe during the stage. I was sitting on [Peter] Sagan for a long time. At the end I was the strongest and it was an amazing moment for me.
"It means a lot for my career. I am 33, have kids but I can still perform with the best."
The 2020 Tour set off two months later than planned due to the coronavirus and under strict health protocols.
The heavy Covid-19 atmosphere weighing on the seaside city was lightened slightly at the start when French government minister Michel Blanquer sent out a rare message of hope the Tour would make it all the way to Paris in three weeks' time.
"You can't rule out the cancellation of the Tour, but it has been so well prepared that the possibilities of it happening are very slim," he said.