The stage contained three brutal climbs before the finish line in the fog on narrow winding roads at Altu d'El Gamoniteiru after 163 km which was this year's queen stage, ie the toughest in this year's competition.
Total three Miguel Angel "Superman" Lopez won the stage after a jerk with around five kilometers left to go from the last climb of 14.6 km with an average slope of 9.8 percent.
Roglic, who took back the red leader's jersey on Wednesday, distanced the others and went in second 14 seconds behind the Colombian.
Finish with pace race on Sunday
- It's nice to have managed the mountains.
The efforts from the last two stages and even those before that are felt.
But there are still some super tough stages left.
Hopefully we can squeeze out the best and finish in a good way, says Roglic according to AP.
The three-week classic will finish in Santiago de Compostela on Sunday 5 September with a 34 km long flat individual pace stage.
Roglic is a recognized good speed skier and won the pace stage that started Vueltan on 14 August.
The Spaniard Roberto Heras is the most successful in the history of the competition since the start in 1935. He has four victories, of which three in a row 2003-2005.
The first came in 2000.
Roglic leads with 2.30 to the good of the home skier Enric Mas.