Cort Nielsen found a gap from his fifth place in the race and made it to a clear victory before Roglic.
- I had a good position and was looking for an opening.
It came with 200 meters left and from there I gave everything I had, says Cort Nielsen, who had a break during the season due to covid-19, in Eurosport's broadcast.
He could only start training three weeks before Vueltan.
Roglic, on his way to defending the title in Vueltan, added another six seconds to runner-up Richard Carapaz and leads by 45 seconds before Saturday's roaring mountain stage.
- I have always wanted to be as complete a cyclist as possible.
Right from the start of this Vueltan, I have wanted to do my best every day, says Roglic, pleased with today's effort, according to Cyclingnews.
On Sunday, the stage race finishes in Madrid.