Time-trial world champion Filippo Ganna won the opening 5.5 mile race against the clock. Gann posted a time 10 seconds faster than his nearest competitor, Jumbo Visma’s Edoardo Affini.
“I didn’t feel I was ready for this race,” said Ganna, also a four-time world champion in individual pursuit, after Saturday’s win.
“My morale wasn’t great after the Tour de Romandie. Now it’s back up!
“It’s been a long time,” he added.
“I hope to recover well by tomorrow because this is only the start of the Giro.” Portuguese Joao Almeida of Deceuninck-Quick Step, who was fourth on the stage behind Norwegian Tobias Foss, set the best time for the candidates for overall victory, 17 seconds behind Ganna.
Almeida’s young Belgian teammate Remco Evenepoel was seventh fastest on his return to competition nine months after plunging into a ravine during a horror crash on the Tour of Lombardy last August.
Race favourites Simon Yates of Britain and Colombian Egan Bernal both finished one-second apart, but over 20 seconds adrift of Almeida, who finished fourth in the Giro last year.