Chris Froome used his climbing prowess to add 43 seconds to his general classification lead, but it was Miguel Angel Lopez who found deep reserves of energy to win stage 11 of the Vuelta a Espana.
Froome and fellow Team Sky rider Mikel Nieve worked together to enable the Brit to extend his GC lead to one minute and 19 seconds, finishing behind Lopez - the Colombian claiming his first stage win at a Grand Tour - for a time bonus of six seconds.
The Tour de France champion was able to sprint past Vincenzo Nibali on the final stretch, the Bahrain-Merida rider finishing third but moving himself up to second in the GC to position himself as Froome's main rival.
Esteban Chaves and Nicolas Roche were unable to keep pace with Froome on the ascent to the finish line at Calar Alto, the former losing close to two minutes and the latter over four.
Froome caught the breakaway on the second category one climb of the wet 187.5-kilometre ride from Lorca, reeling in an attack from Nibali to beat the Italian to the line.
Neither were able to catch Lopez, though, who tore clear in the final kilometre to complete a well-executed race in fitting fashion.
"It was a very complicated stage with the rain, which made it even more exhausting, but I'm really happy because the team has worked so well through this whole Vuelta a Espana," said Lopez.
"My team-mates have been very attentive to Fabio [Aru] and me. This is a big achievement."
GOOD DAY/BAD DAY
By finishing second Froome ensured that he extended his advantage over everyone in the field, taking huge chunks of time out of Chaves and Roche to boost his hopes of becoming just the third man to win the Vuelta and the Tour in the same year.
Quick-Step Floors rider David De La Cruz put himself just three seconds adrift of Chaves and a podium spot, while Wilco Kelderman (Team Sunweb) and Ilnur Zakarin (Katusha) also helped their bids.
Kelderman followed Froome and Nibali in a sprint for the line and is now just one second back from De La Cruz and one clear of Zakarin.
1. Miguel Angel Lopez (Astana) 5:05:09
2. Chris Froome (Team Sky) +00:14
3. Vincenzo Nibali (Bahrain-Merida) +00:14
4. Wilco Kelderman (Team Sunweb) +00:14
5. Romain Bardet (AG2R La Mondiale) +00:31
1. Chris Froome (Team Sky) 45:18:01
2. Vincenzo Nibali (Bahrain-Merida) +01:19
3. Esteban Chaves (Orica-Scott) +02:33
1. Matteo Trentin (Quick-Step Floors) 78 pts
2. Chris Froome (Team Sky) 75 pts
3. Vincenzo Nibali (Bahrain-Merida) 53 pts
KING OF THE MOUNTAINS
1. Davide Villella (Cannondale-Drapac) 38 pts
2. Chris Froome (Team Sky) 21 pts
3. Darwin Atapuma (UAE Team Emirates) 18pts
After a comfortable 80km along the coast from Motril towards Malaga, half the distance of the entire stage, riders will take on two daunting climbs, the second a category two just 17km from the finish line in Antequera. A total of 2,300 metres of slopes makes it a formidable prospect.