EF Education–EasyPost rider Steinhauser claimed his first professional win after going it alone with around 30km to go and finishing the punishing final Passo del Brocon climb after 159km of riding from Selva di Val Gardena.

The 22-year-old broke away with Amanuel Ghebreigzabhier with 50km left, then dropped the Eritrean to close out the win.

"It's something unbelievable. I knew I had good legs, I thought maybe I have the legs to win a stage," said Steinhauser.

"Today already when I rode to the sign on I thought to myself, 'I have good legs, maybe I will win today'."

Steinhauser crossed one minute and 23 seconds ahead of Pogacar who made his own burst from the pink jersey group in the final two kilometres and extended his lead over Daniel Martinez to seven minutes and 42 seconds.

His win came after he finished third on the Giro's 'Queen Stage' on Sunday and looks like the first of many for the nephew of former Tour de France winner Jan Ullrich.

There was a moment when it looked like Pogacar might try to repeat his stunning win on Tuesday when he overtook Giulio Pellizzari in the final kilometre.

"I was just in my zone. I was super nervous on the last climb, I know I had to push all the way to the finish," admitted Steinhauser.

"I heard that he was catching up but it was already 2km to go so I thought 'I will make it'."

Thursday's 18th stage is a 178km flat run between Fiera di Primiero and Padova which will leave space for the sprinters to battle for a stage win.