Three-time champion Primož Roglič has attacked on the climb to the finish on his way to winning stage eight of the Vuelta a España, taking valuable time off Australian Ben O'Connor's overall lead.

Roglič (Red Bull-Bora-Hansgrohe) took his second stage win of the race, with Spain's Enric Mas (Movistar) and Mikel Landa (Soudal Quick-Step) claiming second and third places respectively.

O'Connor (Decathlon-AG2R La Mondiale) crossed the line in 17th place, 46 seconds after Roglič, who also earned a 10-second bonus.

Roglič's effort meant O'Connor's overall lead was cut to three minutes and 49 seconds.

It was expected that Roglič would attempt to make up time on O'Connor on the 159-kilometre ride from Úbeda to Cazorla, a medium mountain stage featuring a sharp uphill finish.

"The opportunity was there, and I went for it," Roglič said.

"It was hard and hot. I was lucky, I had the legs to take it today."

O'Connor said he would look to bounce back in stage nine.

"I was a bit disappointed how I went at the end because I didn't feel super clutch there," he said.

"I don't think we panicked, I thought as a team we were great, and actually had everything under control.

"But it's more [time] than I wanted to give away today. It was definitely not my absolute best day, compared to the others. Hopefully, there'll be better days to come."

Reuters/AAP