The British Grand Tour contender went on the offensive with his BikeExchange team setting the pace early in the day, before Yates attacked 3km from the summit of Sega di Ala.
Yates gained a chunk of time on his general classification contenders, but said he didn’t know Egan Bernal (Ineos Grenadiers) had lost contact.
Speaking after the finish, Yates said: “I was already going full gas, I don’t even realise [Bernal] was dropped until a bit later.
“I was already going full gas so it’s not like I could try and accelerate more to extend the gap.”
Yates has been an unknown quantity in this year’s Giro, riding under the radar in the first week with many speculating he was using conservative tactics early in the race.
But after revealing he’d had some undisclosed problems in the opening stages, climbed to second place at the end of the middle week, before he then lost time on stage 16 to Cortina d’Ampezzo.
Yates has now climbed back onto the podium after stage 17, as he gained almost a minute on Bernal, but he still sits 3-23 off the race lead.
After the finish, he revealed his team had missed the breakaway and that he had been pursuing a stage win: “We missed the breakaway and I wanted to have a go for the stage.
“By the time the break had gone there was only 60km before the first climb - It wasn’t like we had to ride 200km on the front and burn all the team. They did a great job, chapeau to them.”
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