Miguel Angel Lopez (Astana Pro Team) confirmed his status as the strongest climber on the Vuelta a España this year after he claimed the second major summit finish victory at Sierra Nevada, just 24 hours after placing second at La Pandera.
Lopez made his move with Alberto Contador (Trek-Segafredo) on the Alto del Purche, on the steepest part of the ascent, opening up a gap of over a minute on the red jersey group.
When the gap begin to shrink relentlessly in the final four kilometres, Lopez jumped away, and although earlier breakaway rider Adam Yates (Orica-Scott) did his utmost to hold his wheel, it proved impossible for the Briton.
Sixth overall ahead of his teamate Fabio Aru (Astana Pro Team), López said his second win could not have been more timely after his second place the day before, when he could not catch Rafal Majka (Bora-Hansgrohe) with a late counter-attack at La Pandera.
"I couldn't let the team down, yesterday [Saturday] it didn't work out, so today we decided to attack when Contador went for it," Lopez said.
Contador complained later that Lopez had not collaborated with him, but the Colombian explained that he "had a lot of doubts, because it was a long and demanding climb, with a finish at more than 2,000 metres above sea level.
"So I had my doubts – but I found myself with the necessary strength and here we are."
López has now secured Astana's third stage win in this year's Vuelta, all of them on summit finishes after Alexey Lutsenko triumphed in the first week at the Ermita de Santa Lucia and López followed that up with a superb victory in Calar Alto.
The big question is how far López thinks he can go in the overall, given he is now sixth at just inside three minutes from Chris Froome (Sky), the race leader. Froome himself pointed out that while the time trial will now affect how they handle the Colombian, from here on out, if Lopez makes more moves in the mountains then Sky could work harder to reel him in.
"I'm not necessarily surprised he went on the attack today, he's been extremely consistent over last few mountain stages, and we were expecting he would try again," Froome said after stage 15.
"Astana were pulling behind, it was clear they had that objective of the stage, from our side today we were more concentrated on Vincenzo Nibali. But if Lopez continues to take more time in the mountains we will have to respond."