Sagan made it into the day’s six-rider breakaway and held off the chase from Groupama-FDJ and UAE Team Emirates, before dropping his rivals 12km from the finish and riding to a memorable comeback victory.
The former triple world champion said after the stage: “I won with my style, putting on a show.
“I’m very happy, what can I say…finally. I’ve been trying since we started again, at Strade Bianche, Milan San Remo, the Tour de France. I’ve been on the podium a lot of times, but I had my last victory last year in the Tour de France, a long time ago.
“Finally it arrived and I’m very happy.”
Sagan added: “We were in the breakaway all day, I had good legs, and went solo on the uphill before descending with attention on the downhill and then full gas in the final kilometres.”
It was a well-deserved victory for Bora-Hansgrohe, who had been the aggressors through the Tour de France and carried that into the Giro in service of Sagan.
He now has victories in all three Grand Tours and can now focus on the scoring points for the rest of the race.
While Sagan still trials rival sprinter Arnaud Dèmare, who has three stage wins, he is now back within range in his secondary goal in Italy, the ciclamino points jersey.
Dèmare still leads the points table with 167, while Sagan is not far behind on 147.
With three second-place finishes and now a stage victory, Sagan is still poised to take the fight to Demare, and the victories could now start flowing after the huge confidence boost on stage 10.