The gaps in the Grand Boucle’s time trial were certainly big.

Switzerland’s Karin Thürig, twice a world time trial champion, thrashed the field in the difficult 40-kilometre fifth stage from Domaine de Chalain to Clairvaux-les-Lacs.

The Cervelo Lifeforce rider’s nearest challenger was her team-mate, Christiane Soeder of Austria, who was 36 seconds behind.

Third-placed Nicole Cooke, riding for Swift Racing, was 2-40 slower, with the race leader Diana Zilute conceding her yellow jersey as she came in fifth at 3-20.

Britain’s Helen Wyman (Swift) was 21st at 7-36 with Emma Silversides (Lotto-Belisol) 41st at 10-50.

Overall, Thürig now leads Soeder by 39 seconds, with Cooke third at 2-35.

It puts the Cervelo team on the front foot with a healthy lead to defend in today’s penultimate stage, a 102-kilometre leg that take the race to Villard-de-Lans in the Alps.

Cooke will have to attack and hope to gain some time, or else it’ll leave a big job to do on Sunday’s final stage, the 83 kilometres from Guillestre to Sestrieres.

While it’s feasible Thürig could lose a lot of time in the mountains ? she lost 3-46 to Cooke in the final stage of last year’s race, which finished at Arreau in the Pyrenees ? Cooke will know she has to be aggressive.