Sonny Colbrelli sprinted to a surprise win on day three ©Twitter

Sonny Colbrelli sprinted to a surprise victory over Fernando Gaviria and Peter Sagan on day three of the Tour de Suisse in Gansingen.

The Italian, riding for Bahrain-Merida, attacked early in the decisive sprint at the end of the 182 kilometres stage from Oberstammheim.

Sagan was among those to give chase on the left hand side of the road as Gaviria attacked on the opposite side.

Sagan, the Bora-Hansgrohe and Slovakian world road race champion who won stage two yesterday, then made the mistake of jumping across to Gaviria's wheel.

This allowed Colbrelli to hold-off his bigger rivals for a superb win in this International Cycling Union WorldTour event. 

Gaviria, the Colombian riding for Quick-Step Floors crossed second and Sagan third.

All three were awarded the same time of 4 hours 39min 51sec.

The stage did not threaten the overall standings, where home rider Stefan Küng still leads a BMC Racing 1-2-3-4 after the opening team time trial.

Olympic road race champion Greg van Avermaet, Australia's Richie Porte and United States' Tejay van Garderen all lie three seconds behind in second, third and fourth respectively.

Overall contenders may come to the fore tomorrow in a mountainous 189km stage from Gansingen to Gstaad.