Chris Froome expects his rivals for Tour de France victory to attack with increasing urgency after preserving his commanding lead on the first of four stages in the Alps.

The 30-year-old Team Sky leader successfully countered attacks from nearest challenger Nairo Quintana (Movistar) early and late on the 161-kilometres 17th stage from Digne-les-Bains to Pra Loup as German Simon Geschke (Giant-Alpecin) won.

"He's running out of opportunities," Froome said of Quintana. "There's only three more stages left to race. They're really tough stages.

"I've got to admit I was quite surprised to see him jumping around 50, 60km into the race today. A few of the guys going for it really early. (Alejandro) Valverde also, (Alberto) Contador.

"Definitely getting the feeling it's an all-or-nothing approach at this stage in the race."

Quintana tried to launch an early break, but Froome's Team Sky squad hunted him down and when the Colombian climber twice accelerated on the concluding ascent to the small ski resort, Froome chased himself.

The Kenya-born Briton finished seven minutes 16 seconds behind Geschke on the same time as Quintana to preserve his advantage of 3mins 10secs ahead of Sunday's conclusion in Paris.

It was the first of four stages in the Alps and Thursday's 186.5km stage from Gap to Saint-Jean-de-Maurienne is sure to provide another test.

Froome believes anyone attacking early on a stage is taking a big gamble.

"Attacking towards the beginning of a stage, that's a pretty big risk," he added. "If you do get away you're potentially going to spend 100km up the road, spending a lot of energy which could leave you in quite a deficit for the next few stages."

Contador (Tinkoff-Saxo) lost more time after a crash on the challenging descent of the day's penultimate climb, the Col d'Allos.

The Spaniard trailed in 2:17 behind Froome and Quintana as his bid for a Giro d'Italia-Tour double faded further. He moved fifth but is 6:40 behind.

"We can only expect him to attack even earlier in the next few stages," Froome said.

Valverde, Quintana's team-mate, conceded six seconds to Froome and the Colombian, but moved up to third overall after American Tejay van Garderen (BMC Racing) was forced to abandon due to illness.

That, coupled with Contador's crash, saw Geraint Thomas (Team Sky) move up to fourth overall, giving hope of two Britons on the podium.

Wednesday was the third anniversary of Sir Bradley Wiggins' maiden British win, when Froome finished the Tour second.

Froome, who had words of consolation for Van Garderen, said: "It would be an absolute dream to have him (Thomas) also on the podium. But obviously at this point keeping the yellow jersey, that's our main focus."

Team Sky will likely face further tactical tests in the next three days before Sunday's ceremonial finish on the Champs-Elysees.

The British team sent Richie Porte and Nicolas Roche in the day's breakaway, but neither really helped Froome in the way Quintana and Valverde received support from their Movistar team-mates.

Froome was unfazed, though, monitoring and chasing only his two rivals for overall victory.

Defending champion Vincenzo Nibali (Astana) had an active day without making too much of an impression, conceding 15secs to fall 8:04 adrift in seventh.

Nibali made his move on the Col d'Allos and tried to make gains on the perilous descent – Contador and Thibaut Pinot (FDJ) were among those who crashed - but Froome stuck to his wheel.

As Froome moved a step closer to a second Tour title in Paris on Sunday, Geschke celebrated a rare win.

He said: "It was not the plan to cry live on TV, but I can't help it. This is my third victory as a professional and to do it here at the Tour – I was dreaming since 15 years (old) of this moment."