Van Garderen opted to attack inside the final five kilometres of a climber friendly route, with the American then chased by Colombia's Angel Lopez and Warren Barguil as they approached the summit of the ascent up Rettenbachferner.

The American rider had not posed a major threat to the overall classification due to lying some way adrift of the race lead, which was held by Wilco Kelderman of the Netherlands.

Kelderman had been dropped earlier on the final climb, where the general classification riders had made contact and surpassed the day’s breakaway riders Mathias Brandle of Austria and Iljo Keisse of Belgium.

While Lopez and Barguil worked together in a desperate attempt to close on Van Garderen in the closing kilometres, the American, who will not compete at the Rio 2016 Olympics due to fears over the Zika virus, continued to power away.

Van Garderen eventually crossed the line in a time of 6hr 26min and 13sec to earn victory in the queen stage of the International Cycling Union (UCI) World Tour race.

The two chasers finished 16 seconds adrift of the American, but it proved enough for Barguil to assume the lead of the general classification.

He lies 21 seconds ahead of Lopez, who claimed second on the stage, while the United States’ Andrew Talansky is a further three seconds behind.

The classification could change dramatically tomorrow with a 16.8 km time trial due to take place in Davos.

A 117.7 kilometre stage in Davos will then bring the race to a close on Sunday (June 19).