Joe Dombrowski won stage four of the Giro d'Italia as Alessandro De Marchi took the pink jersey, but Simon Yates lost ground in the battle of the main favourites behind.
Dombrowski took his first Grand Tour stage win as the UAE Team Emirates rider attacked out of the breakaway at the end of a 187km stage from Piacenza to the ski station in Sestola, raced in wet, cold and windy conditions.
But as the main peloton followed up the final climb, Yates was distanced by a small group including Egan Bernal, Hugh Carthy and Mikel Landa – conceding 11 seconds.
"I’m really happy with today," Dombrowski said. "I knew De Marchi was probably the strongest rider in the break so I knew if I stuck to his wheel I would be in a good spot."
Dombrowski took victory by 13 seconds from Israel Start-Up Nation’s De Marchi, who now has a 22-second advantage over the American in pink.
"The goal was the maglia rosa," De Marchi said. "I started thinking about it two days ago but I didn’t tell anybody.
"I knew this was a day when a good move could go… then it was about a bit of luck and here we are – I’m without words."
Bahrain-Victorious’ Landa sparked the late attacks in the group of main favourites, quickly joined by Bernal, Carthy and Aleksandr Vlasov as they built a small advantage over their rivals.
EF Education Nippo’s Carthy is now up to 10th, one minute 38 seconds off pink, one second ahead of the Ineos Grenadiers’ Bernal.
Team BikeExchange’s Yates sits 16th, one minute 49 seconds down on De Marchi’s time.
De Marchi's team-mate Dan Martin finished 19th on the stage and is 2:08 adrift of the leader and 21st overall, while Team DSM's Nicolas Roche was 75th and is now 65th in the general classification.