Volta a Catalunya: Chris Froome loses 26 minutes on leader Alejandro Valverde
Chris Froome's hopes of victory at the Volta a Catalunya were dashed as the Team Sky rider lost 26 minutes on his rivals in Saturday's penultimate stage.
Alejandro Valverde extended his overall lead as his Movistar team dominated but stage victory was snatched from him by Daryl Impey in a sprint to the line.
Froome, riding his first European race of 2017, had moved second with a strong finish behind Valverde on Friday.
But he struggled on the 190km run from Tortosa to Reus, finishing way behind.
"I said coming into this race that I was here to suffer this week and that's exactly what I've got out of it," said Froome.
"Personally it was great to be up there yesterday with the best guys and to be feeling that good this early on in the season, but days like today are really tough. We just have to learn from them and move on."
Valverde now leads Alberto Contador, who moved up to second, by 53 seconds, with Britain's Adam Yates in fourth, one minute and 21 seconds behind the Spaniard.
Sunday's final stage in Spain is a relatively flat 138km route that begins and ends in Barcelona, with overall victory for Valverde now all but assured.
Geraint Thomas, who began the stage in seventh overall, was also distanced after Froome and Team Sky were among those dropped by an attacking move after the day's opening climb.
The gap only widened over the day, and Froome's group were 21 minutes behind by the time they went over the final climb, the snow-topped category one Alt de la Mussara.
Up the road on the descent, Italians Alessandro de Marchi of BMC and Dario Cataldo of Astana broke clear with 15km to go, but the pair were caught in the final metres, with South African Impey just edging ahead of Valverde.
Team Sky sport director Nicolas Portal said: "We made a big mistake. I'm not going to try to make an excuse. There is no excuse.
"The guys have been brilliant up until today. It looks like it was a positioning issue. The guys weren't in the top positions on the first descent and this is what can happen.
"It's a good reminder for us that it can happen to anyone. It's always bad when it happens, but maybe it's better to happen here, and we learn from it, than in some of the bigger races we will have this season."
Stage six result:
1. Daryl Impey (RSA/Orica) 4hrs 34mins 14secs
2. Alejandro Valverde (Spa/Movistar) Same time
3. Arthur Vichot (Fra/FDJ)
4. Petr Vakoc (Cze/Quick-Step)
5. Allesandro de Marchi (Ita/BMC)
6. Nick van der Lijke (Ned/Roompot)
7. Dario Cataldo (Ita/Astana)
8. Lennard Kamna (Ger/Team Sunweb)
9. Cyril Gautier (Fra/Ag2r)
10. Daniel Martin (Ire/Quick-Step)
74. Chris Froome (GB/Team Sky) +26min 38secs
86. Geraint Thomas (GB/Team Sky) Same time
1. Alejandro Valverde (Spa/Movistar) 22hrs 18mins 35secs
2. Alberto Contador (Spa/Trek) +53secs
3. Marc Soler (Spa/Movistar) +1min 6secs
4. Adam Yates (GB/Orica) +1min 21secs
5. Tejay van Garderen (US/BMC Racing) +1min 24secs
6. Daniel Martin (Ire/Quick-Step) +2mins 19secs
7. Steven Kruijswijk (Ned/LottoNL) +2mins 46secs
8. Carlos Verona (Spa/Orica) +2mins 50secs
9, George Bennett (NZ/LottoNL) +2mins 51secs
10. Romain Bardet (Fra/AG2R) +2mins 55secs
31. Chris Froome (GB/Team Sky) +27mins 5secs
32. Geraint Thomas (GB/Team Sky) +28mins 18secs