Simon Yates' grip on the race lead in the Vuelta a España weakened a little during stage 17 on Wednesday as the Mitchelton-Scott racer lost eight seconds to his closest GC pursuer, Alejandro Valverde (Movistar).
Mitchelton-Scott's Jack Haig and Yates' brother Adam did sterling work keeping the little group of favourites under control on the brutally steep ascent of Mount Oiz.
But when Valverde laid down one of his trademark explosive accelerations close to the summit, Yates could not respond. He finished eight seconds behind Valverde, in 17th place.
After the previous day's small but unexpected gain of seven seconds on Valverde in the Torrelavega time trial, the Briton has now suffered an almost equally minor, unexpected time loss both to Valverde and the up-and-coming Spaniard Enric Mas (Quick Step Floors).
Given that stage 17 was the mountain stage that he feared the most, it was perhaps not as much of a dangerous setback as it could have been.
With Steven Kruijswijk (LottoNL-Jumbo), previously third overall in trouble on the climb, shedding nearly a minute and finishing alongside Nairo Quintana (Movistar), Yates was asked if he felt now that the Vuelta was a two-horse race between himself and Valverde.
"I don't. There are a lot of hard stages to come, including Andorra, and the gaps are still small behind," Yates told reporters. "I'd never count anybody out of this race."
Losing eight seconds was not a blow to his morale, either.
"There's no shame in losing a few seconds to Alejandro. He and [Enric] Mas [ now third overall - ed.] are both classy riders. I felt good and I truly believe the Andorra stages are much better for me."
The dense fog at the summit made it hard to see what was actually happening as television images of the GC group, barring a struggling Quintana, became increasingly scant.
"Nobody really attacked on the climb," Yates said. "Valverde tried early on but my brother Adam and Jack were riding hard on most of the climb" - reeling Valverde in the process - "but then with 1.5 kilometres [Miguel Angel] Lopez went for it.
"But Adam closed him down. That was it. It turned into a bit of a stalemate. Then Alejandro opened the sprint at the top and that's where the gaps were created."
One rider who has lost a lot more time unexpectedly was Quintana, but Yates continued to insist that the gaps between him and the Colombian were fairly small.
"Of course I"m happy to put some time into him today, but there's not much of a time loss. In Andorra, he'll try and go early, so he'll make my life a bit more difficult there," Yates said.
Asked to compare his condition to the Asturian ascent to Praeres, similarly steep, if shorter, and where he took the leader's jersey back last Saturday, Yates said his legs were similar.
"The numbers were slightly better that day, I think, though I'd have to confirm that, but of course we're that much further into the race.
"Of the stages left, this was the one I was most afraid of. I know the Andorra stages extremely well and they suit me better."
Yates is now a day closer to Madrid and overall victory, but Valverde's success in what was effectively a skirmish in the main battle still has seen no change at the top of the ranking. The definitive answer to whether he could yet suffer a jour sans of the type that cost him the Giro d'Italia will only be provided on Saturday evening, atop the Coll de la Gallina.