Simon Yates rode himself into Vuelta a Espana contention with a stirring display on Saturday as he came home 39 seconds behind stage 14 winner Robert Gesink.
The Orica BikeExchange rider trailed general classification leader Nairo Quintana by three minutes and 25 seconds prior to the 196km route, but he is now a rival for the title after shaving a minute off his deficit.
Yates' break on the third of four climbs from Urdax-Dantxarinea to Aubisque saw him pull away from the peloton, and although he could not reel in the leading group he was able to gain valuable time.
At the front Gesink was part of a large breakaway on a gruelling day, the LottoNL - Jumbo rider able to hold off Kenny Elissonde and Egor Silin to take the stage win atop the Col d'Aubisque.
While Yates was putting himself firmly in the GC mix, the leading two produced a thrilling battle on the final climb, Quintana regularly pushing away from Chris Froome only for the Team Sky rider to reel him in.
Eventually the pair finished together, meaning Quintana holds onto the leader's red jersey and a 54-second advantage over his British rival.
On what had been described by Movistar director sportive Jose Luis Arrieta as "the hardest Grand Tour stage of the season" the peloton quickly split into two groups, with 39 riders in the breakaway.
Dimension Data's Omar Fraile put himself into King of the Mountains contention as he took maximum points atop the first two climbs before being dropped on a relentless day.
The second climb up Col du Soudet began to thin the leading group out but it was not until the penultimate ascent that the stage burst into life, Yates' bold move setting the tone for a dramatic finale.
Catching the leaders proved too much for the British rider, but the time he gained throws him into contention for the title in the remaining seven stages.
Gesink bided his time before attacking on the final climb, the Dutchman going beyond the six leaders and only taking Elissonde (FDJ) - who is the new mountains leader - with him.
The duo were joined by Silin (Katusha) but neither could deny Gesink his maiden Grand Tour success, however focus quickly turned to the GC battle.
Quintana and Froome had played a waiting game in the peloton as the leaders stretched their advantage during the day but their individual battle came to the fore as the Colombian pushed with four kilometres to go.
Froome was not in the mood to let his rival go, though, and he kept pace with Quintana all the way to the finish line to ensure he holds onto second place overall.