Britain's Chris Froome finished more than two minutes behind new leader Vincenzo Nibali on a rainy stage six of the Criterium du Dauphine on Friday.
Froome, who started the day 52 seconds ahead of Nibali, is now seventh, one minute 21 seconds behind the Italian.
Nibali and stage winner Rui Costa of Portugal were part of a long-range breakaway in the French Alps.
Britain's leading rider is now Simon Yates, who finished fifth on the day and is fourth overall.
Yates has taken the lead in the best young rider classification, while race leader Nibali is 29 seconds ahead of Costa with two stages left.
Astana rider Nibali was seventh in the Criterium last year and went on to win the Tour de France.
The Criterium concludes in Modane on Sunday.
Stage 6 results
1. Rui Costa (Por/Lampre) 4hrs 29 mins 23 secs
2. Vincenzo Nibali (Ita/Astana) +5secs
3. Alejandro Valverde (Spa/Movistar) +38secs
4. Tony Gallopin (Fra/Lotto) +39secs
5. Simon Yates (GB/Orica) +1mins 24secs
6. Daniel Martin (Ire / Cannondale) +1mins 46secs
7. John Gadret (Fra/Movistar) +1mins 48secs
8. Tiesj Benoot (Bel/Lotto) +1mins 59secs
9. Chris Froome (GB/Team Sky) +2mins 12secs
General Classification after stage 6:
1. Vincenzo Nibali (Ita/Astana) 22hrs 34mins 17secs
2. Rui Costa (Por/Lampre) +29secs
3. Alejandro Valverde (Spa/Movistar) +30secs
4. Simon Yates (GB/Orica) +35secs
5. Tejay van Garderen (US/BMC Racing) +42secs
6. Benat Intxausti (Spa/Movistar) +57secs
7. Chris Froome (GB / Team Sky) +1mins 21secs