Swiss Stefan Kung won Thursday's stage 18 time-trial as Spaniard Enric Mas retained the overall lead at the Vuelta a Espana.
But four-time winner Primoz Roglic finished more than 30 seconds quicker than Mas and trimmed down the Movistar rider's lead to 1min 37sec as the Slovenian leapfrogged Felix Gall into second place.
With just three stages left, including two successive mountain top finishes, Mas is looking increasingly likely to finally claim his first home Grand Tour.
Era uno de los favoritos, no decepcionó y Stefan Küng se lleva su segunda contrarreloj en La Vuelta. Revive el último kilómetro gracias a @CarrefourES pic.twitter.com/toHk0HLHYL
— La Vuelta (@lavuelta) September 10, 2026
"The whole race went well, I lost less time than I expected, I'm happy with my day," said Mas.
The 31-year-old has finished second three times, to Simon Yates in 2018, to Roglic in 2021 and to Remco Evenepoel the year after that.
He was also third behind Roglic and Australian Ben O'Connor two years ago.
Roglic, 36, is his closest challenger after finishing Thursday's 32.1km time-trial in fourth, just 19sec behind Kung, with Briton Callum Thornley second at 3sec and Portugal's Joao Almeida third at 9sec.
"In the end, you have to win. (It) doesn't matter how big the margin is," said the Tudor Pro Cycling rider, who won his 24th time-trial as a professional.
"I'm super happy to take the win here. I'm alone on the podium today, but it's a victory from the whole team."
Roglic finished 33sec quicker than Mas and 1:28 faster than Gall.
Austrian Gall is just over three minutes behind Mas but has a buffer of more than two minutes to fourth-placed Richard Carapaz, who finished eighth at July's Tour de France.
Briton Oscar Onley, who is fifth overall, extended his lead in the best young rider white jersey category to almost a minute ahead of Slovenian Jakob Omrzel.
Friday's stage 19 is a hilly 210.8km ride, starting from Velez-Malaga and culminating in an altitude finish at Penas Blancas.