By Julien Pretot
PINEROLO, Italy (Reuters) - Alberto Contador took a calculated risk to attack on a treacherous descent in a bid to salvage his hopes of a fourth Tour de France title on Wednesday.
"It was a very dangerous descent," the Spaniard said after the 17th stage. "I was off the front, I saw I could attack and the important thing is to pull back time every day."
The 28-year-old Contador, who lost crucial ground in the first stage after being held up behind a pile-up, sprang from the pack at the top of the Pramartino with Samuel Sanchez and the duo went all out to open up a gap on the descent into Pinerolo.
Contador and Sanchez were reeled in by a group containing Luxembourg's Schleck brothers, Andy and Frank, and Australian Cadel Evans with the finish line in sight.
However Contador gained time on overall leader Thomas Voeckler of France, who went off the road in spectacular fashion, losing 27 seconds in the process.
Contador, unbeaten in all the grands Tours he has entered since 2007, had already gone on the attack on Tuesday after fully recovering from a knee problem he sustained in a crash during the first week.
"Today everybody knew I would attack which is different to yesterday, and the good weather made for easier conditions," Contador told reporters.
Voeckler was the only other favorite to take risks on the tree-lined, narrow downhill as the Schleck brothers, who believed the descent was too dangerous, once again failed to attack, seemingly content with the waiting game being played out among the top guns.
"I'm not surprised the Schlecks didn't attack, but I'm doing my race anyway and I got a good reward; Voeckler is a very, very great rider and whatever time I can pull back on him is good," said Contador.
The Spaniard still trails Voeckler by three minutes 15 seconds, with Evans in second place 1:18 off the pace. Frank Schleck lies in third place, 1:22 behind Voeckler, while his younger brother Andy, runner-up in the last two editions of the Tour, is 2:36 off the pace.
Evans, who gained three seconds over Contador in Tuesday's descent to the finish in Gap, stayed safe on Wednesday.
"It was sketchy. With the shadows and stuff it was really hard to see. I didn't want to take too many risks," the 2009 world champion told reporters.
"Voeckler went off the road twice in front of me. It makes you take things a bit more cautiously. There was a gap and I got caught behind Andy and could not get around him."
Contador is expected to be on the attack again on Thursday in a tough stage finishing at 2,645 meters above sea level at the top of the Col du Galibier in a stage also featuring the ascents to the Col d'Agnel, at 2,744 meters, and the Col d'Izoard.
(Editing by Clare Fallon)