Lenny Martinez became the new Vuelta a Espana leader, but a frantic stage six saw the race swing Jumbo-Visma’s way.
Jumbo-Visma’s US rider Sepp Kuss won Thursday’s mountain stage, ahead of Martinez and a large breakaway group.
Jonas Vingegaard and Primoz Roglic – both team-mates of Kuss – gained 32 seconds on 2022 winner Remco Evenepoel, the previous leader.
Dutch team Jumbo-Visma are aiming to become the first team to win all three Grand Tours in a single season.
Slovenia’s three-time Vuelta winner Roglic, 33, claimed his first Giro d’Italia title in May before Denmark’s Vingegaard, 26, defended his Tour de France title in July.
World time trial champion Evenepoel’s Soudal Quick-Step team let a group of 40 riders go six minutes clear on the 183.5km stage from La Vall d’Uixo to the Javalambre Observatory.
On the steep ramps of the final climb, Kuss went solo with 2.5km remaining to win ahead of Groupama-FDJ’s 20-year-old French hope Martinez.
Further down the mountain, Roglic and Vingegaard attacked to close the gap on Evenepoel in the overall standings, with the 23-year-old Belgian now just five seconds ahead of Vingegaard and 11 clear of Roglic.
Britain’s Geraint Thomas tried to stick with Evenepoel but crossed 53 seconds after him, leaving the Ineos Grenadiers rider about two minutes behind the main favourites in 23rd place overall.
Stage six results
1. Sepp Kuss (USA/Jumbo-Visma) 4hrs 27mins 29secs
2. Lenny Martinez (Fra/Groupama-FDJ) +26secs
3. Romain Bardet (Fra/DSM-Firmenich) +31secs
4. Mikel Landa (Spa/Bahrain Victorious) +46secs
5. Marc Soler (Spa/UAE Team Emirates) +46secs
6. Wout Poels (Ned/Bahrain Victorious) +1min 3secs
7. Einer Rubio (Col/Movistar) +1:05
8. Cristian Rodriguez (Spa/Arkea-Samsic) +1:12
9. Steff Cras (Bel/TotalEnergies) +1:12
10. Jefferson Alveiro Cepeda (Ecu/Caja Rural-Seguros RGA) +1:26
General classification after stage six
1. Lenny Martinez (Fra/Groupama-FDJ) 21hrs 40mins 35secs
2. Sepp Kuss (USA/Jumbo-Visma) +8secs
3. Marc Soler (Spa/UAE Team Emirates) +51secs
4. Wout Poels (Ned/Bahrain Victorious) +1min 41secs
5. Steff Cras (Bel/TotalEnergies) +1:48
6. Mikel Landa (Spa/Bahrain Victorious) +1:58
7. Jefferson Alveiro Cepeda (Ecu/Caja Rural-Seguros RGA) +2:06
8. David de la Cruz (Spa/Astana-Qazaqstan) +2:23
9. Remco Evenepoel (Bel/Soudal-Quick-Step) +2:47
10. Enric Mas (Spa/Movistar) +2:50