Alejandro Valverde of the Caisse d'Epargne team took control of the Dauphine Libere race on Thursday after leaving Australia's Cadel Evans behind on the gruelling Mont Ventoux climb.
The 29-year-old defending champion established a two-minute lead over his Silence-Lotto rival when he powered ahead in the company of Polish rider Sylvester Szmyd, of the Liquigas team.
The Pole took the stage win, accelerating first over the line at the summit of the 1,909-metre high mountain.
"When I found myself in front I started to get stressed," said the 31-year-old from Warsaw. "I am not in the habit of being in a winning position. It was a classy victory." Valverde planned his breakaway as the riders tackled the climb concluding the 154 kilometre stage from Valence.
The Spaniard, who dons the yellow jersey of race leader, has now established a 16-second lead over Evans in the overall race standings.
"I was happy with the time trial I did yesterday and even though I was not at my best, I felt okay," said Valverde.
"So today I felt I really had the legs to attack 10 kilometres from the finish and put everything into it."
Evans said: "It was a bizarre race. It seemed not many riders want to win the Dauphine.
"It's hard to have the responsibility of wearing the yellow jersey as well as coping with the wind on the final stretch, that's tough on the Ventoux. I was expecting Contador to do more," added the racer from Katherine, Northern Territory.
Astana rider Alberto Contador, winner of the Tour de France in 2007, finished eighth on Thursday and is now third-placed in the overall race standings.
Contador said he was saving his strength for next month's Tour de France.
"I stayed with Evans and chose not to get in a fight. Evans is in great form but he had to work extra hard. When your opponent is hanging onto your back wheel you are always concerned he may launch an attack," he said.
Although Szmyd came second in the same setting here two years ago, it was the first ever stage win in a major race for the Pole.
On Friday, the riders face a 106-kilometre stage from Gap to Briancon. The race is a key build-up event before the start of the Tour de France on July 6.
Stage
1. Sylvester Szmyd (POL/LIQ) 4hr 35min 04sec.
2. Alejandro Valverde (ESP/GCE) at 0:00.
3. Haimar Zubeldia (ESP/AST) 1:14.
4. Robert Gesink (NED/RAB) 1:50.
5. Jakob Fuglsang (DEN/SAX) 1:59.
6. Cadel Evans (AUS/SIL) 2:10.
7. David Moncoutié (FRA/COF) 2:13.
8. Alberto Contador (ESP/AST) 2:13.
9. Vincenzo Nibali (ITA/LIQ) 2:16.
10. Vladimir Efimkin (RUS/ALM) 2:20.
Selected
35. Ivan Basso (ITA/LIQ) 8:14.
77. Oscar Pereiro (ESP/GCE) 17:56.
130. Tom Boonen (BEL/QST) 24:55.
Overall
1. Alejandro Valverde (ESP/GCE) 15h 23min 17sec.
2. Cadel Evans (AUS/SIL) at 0:16.
3. Alberto Contador (ESP/AST) 1:04.
4. David Millar (GBR/GRM) 1:43.
5. Haimar Zubeldia (ESP/AST) 2:21.
6. Robert Gesink (NED/RAB) 2:34.
7. Vincenzo Nibali (ITA/LIQ) 2:34.
8. Mikel Astarloza (ESP/EUS) 2:44.
9. Sylvester Szmyd (POL/LIQ) 3:05.
10. Jakob Fuglsang (DEN/SAX) 3:35.