Primoz Roglic tightened his grip on a third successive Vuelta a Espana title after France's Clement Champoussin ambushed the favourites by claiming Saturday's penultimate stage for the biggest win of his young career.
Ahead of the final-day time trial double defending champion Roglic leads by a defendable 2min 38sec from Movistar rider Enric Mas, while Australian Jack Haig of Bahrain Victorious climbed to third almost five minutes adrift.
Miguel Angel Lopez of Movistar, placed third overnight and the 18th stage winner, dramatically downed tools midway through the day.
The Colombian jumped off his bike and into a team car after hopes of a podium finish were ruined when he and Egan Bernal were in a group dropped on the third climb.
One of those not caught out by Ineos' ploy to try and disrupt the action was AG2R-Citroen's surprise 23-year-old stage winner who only turned professional a year ago, and with this first win he raised a solitary finger in celebration before thumping his chest at the finish line.Â
Finding himself in the lead pack after taking part in an early break Champoussin attacked in the final kilometre, gasping for breath and straining every sinew as his companions allowed him to edge away.
"I hung on....and a little way from the finish I was lucky they looked at each other," Champoussin said after the main contenders hesitated to follow until too late.
"It was tough, but the favourites were tired too."
Pacing himself patiently all the way from the seaside start at Sanxenxo, Roglic edged his key rivals at the end as he followed the winner over the line with Adam Yates and Mas hot on his tail.
"I'm super happy with the place I finished in today and with the way it went. I was mainly looking at Yates and Mas," the Slovenian Jumbo-Visma rider said.
Sunday's final stage is an arduous 33km run to Santiago de Compostela.Â
It will be a test of nerves for the easily-spooked Slovenian rider despite his large lead. Cycling history is littered with last-day tales of woe, not least his own.
Roglic is the Olympic time-trial champion, but famously lost a major lead in a time trial on the final weekend of the 2020 Tour de France.
"I'm looking forward to tomorrow. We've been waiting for this and finally here we are," said Roglic, who could win his fourth stage of this Vuelta on Sunday and his third straight edition of the race.
With five short but hard mountain passes on a tough stage in Galicia on Saturday, South African Ryan Gibbons had a gut-wrenching afternoon as his long-range solo escape wilted with less than 2km to go.
BAD DAY
"I tried to drop them all a few times," said the Briton Yates, who joined Ineos this season with the Vuelta his first Grand Tour with them.
Giro champion and 2019 Tour de France winner Bernal also let slip the under-25's white jersey to Swiss Gino Mader, also of Bahrain, with the Colombian saying at the finish line he would not push to win it back on Sunday.
"We did what we could today. We tried to blow the race open and we succeeded at least in that," said Bernal, who professes to care more about racing than winning.
Australian Michael Storer of the DSM team extended his King of the Mountains lead after taking part in an early attack. The 24-year-old Storer has also sneaked into the top 10 overall and won stages seven and 10, stealing the thunder from teammate Romain Bardet.
A year after a horrific crash on the Tour of Poland, Dutch sprinter Fabio Jakobsen of Deceuninck Quick-Step will provide a feel-good factor as he climbs the podium Sunday after winning three stages to seal a remarkable recovery.Â
STAGE 20 RESULTS
1. Clément Champoussin (FRA) - AG2R-Citroën Team - 5hrs21mins50sec
2. Primož Roglic (SLO) - Jumbo-Visma - +6sec
3. Adam Yates (GBR) - INEOS Grenadiers - +8sec
4. Enric Mas (ESP) - Movistar Team - +8sec
5. Jack Haig (AUS) - Bahrain Victorious - +12sec
6. Chris Hamilton (AUS) - Team DSM - +16sec
7. Mikel Bizkarra (ESP) - Euskaltel-Euskadi - +23sec
8. Ryan Gibbons (RSA) - UAE Team Emirates - +26sec
9. Gino Mäder (SUI) - Bahrain Victorious - +26sec
10. Floris De Tier (BEL) - Alpecin-Fenix - +50sec
11. Jan Hirt (CZE) - Intermarché-Wanty-Gobert Matériaux - +1min05sec
12. Lilian Calmejane (FRA) - AG2R-Citroën Team - +1min09sec
13. Sylvain Moniquet (BEL) - Lotto-Soudal - +1min13sec
14. Stan Dewulf (BEL) - AG2R-Citroën Team - +1min15sec
15. Nicholas Schultz (AUS) - Team BikeExchange - +1min35sec
16. Daniel Navarro (ESP) - Burgos-BH - +2mins25sec
17. Felix Großschartner (AUT) - BORA-hansgrohe - +6mins55sec
18. David De La Cruz (ESP) - UAE Team Emirates - +6mins55sec
19. Egan Bernal (COL) INEOS - Grenadiers - +6mins55sec
20. Steven Kruijswijk (NED) - Jumbo-Visma - +6mins55sec
GENERAL CLASSIFICATION
1. Primož Roglic (SLO) - Jumbo-Visma - 83hrs11mins27sec
2. Enric Mas (ESP) - Movistar Team - +2mins38sec
3. Jack Haig (AUS) - Bahrain Victorious - +4mins48sec
4. Adam Yates (GBR) - INEOS Grenadiers - +5mins48sec
5. Gino Mäder (SUI) - Bahrain Victorious - +8mins14sec
6. Egan Bernal (COL) - INEOS Grenadiers - +11mins38sec
7. Sepp Kuss (USA) - Jumbo-Visma - +13mins42sec
8. Guillaume Martin (FRA) - Cofidis - +16mins11sec
9. David De La Cruz (ESP) - UAE Team Emirates - +16mins19sec
10. Felix Großschartner (AUT) - BORA-hansgrohe - +20mins30sec
11. Odd Christian Eiking (NOR) - Intermarché-Wanty-Gobert Matériaux - +20mins46sec
12. Steven Kruijswijk (NED) - Jumbo-Visma - +24mins50sec
13. Juan Pedro López (ESP) - Trek-Segafredo - +26mins18sec
14. Geoffrey Bouchard (FRA) - AG2R-Citroën Team - +43mins59sec
15. Rémy Rochas (FRA) - Cofidis - +47mins47sec
16. Clément Champoussin (FRA) - AG2R-Citroën Team - +52mins05sec
17. Damiano Caruso (ITA) - Bahrain Victorious - +1hr02mins56sec
18. Sam Oomen (NED) - Jumbo-Visma - +1hr04mins36sec
19. Óscar Cabedo (ESP) - Burgos-BH - +1hr06mins46sec
20. Gianluca Brambilla (ITA) - Trek-Segafredo - +1hr16mins18sec