Alberto Contador again attempted to blow the race apart, but this time his rivals were privy to his plan, keeping the Spaniard contained until the final climb to the line in stage 18.
While the breakaway animated the stage win with Sander Armée (Lotto Soudal) taking his first professional victory, 10 minutes later the small bunch containing the GC rivals – less Fabio Aru (Astana) who had escaped earlier – arrived at the bottom of the three-kilometer long finish climb.
Peter Stetina pulled full-gas on the lower slopes with Alberto Contador on his wheel, and when he could give no more, Team Sky continued with the fierce pace. The group exploded.
Contador held firm to Chris Froome's wheel, and when the race leader attacked within the final 800 meters, he immediately reacted.
Only Contador and Michael Woods (Cannondale-Drapac) could follow Froome's acceleration, and when Froome decided it was not in his best interest to do all the work to the line, Contador finished it off for the last steep 400 meters.
Contador led Woods and Froome over the line 12 seconds behind Fabio Aru, who had built a lead well over a minute at one point. Moments later 3rd placed Wilco Kelderman (LottoNL-Jumbo) and fourth placed Ilnur Zakarin (Katusha-Alpecin) arrived, minimizing the damage to four seconds.
"We knew it would be a difficult day to gain time," explained Contador. "The race started, and I wanted to make moves, and then the race restarted on the Collada de la Hoz, and the moves were pretty predictable.
"I got involved because I thought there were riders having a bad day, but it was difficult to gain time on a stage like today. The main thing is that some rivals were dropped on the Collada de la Hoz, which isn't a very difficult climb, so that is significant in view of the l'Angliru on Saturday."
While Contador's attacks were controlled on the Collada de la Hoz, the penultimate climb of the 169-kilometer stage, and his principal opponents limited their losses on the final short uphill blast, the next two days' agenda has already been written. El Pistolero, definitely finding his legs in the third week, will end the last race of his career with all guns firing.
"The differences [in time] really don't make a difference today. I think the conclusion that has to be drawn that I have in my head is that the legs work, and that's the most important thing. Now I have to recover thinking about Saturday. The l'Angliru is a very difficult climb, and I hope that I have legs," he concluded.