The 23-year-old Team Sunweb rider prevailed with a time of 4 hours 59min 53sec for the 186 kilometres stage from Fiesch to Gommiswald.

Australia’s Richie Porte of the BMC Racing Team finished sixth today and extended his lead in the general classification to 32 seconds over Andersen’s team-mates Wilco Kelderman and Sam Oomen of The Netherlands.

Compatriot Nathan Haas of Katusha-Alpecin was today’s runner-up, finishing 10 seconds behind Andersen.

Spain’s Gorka Izagirre of Bahrain-Merida was a further 14 seconds back in third.

Austria’s Michael Gogl of Trek-Segafredo attacked first from today’s six-man breakaway with two kilometres remaining, but he faded away and ended up in seventh place.

Stage seven is scheduled for tomorrow and is spread across a distance of 170.5km from Eschenbach to Arosa.

The second stage of the British-based 2018 Women’s Tour also took place today with the United States’ Coryn Rivera of Team Sunweb coming out on top to move into the general classification lead.

Rivera crossed the finish line centimetres ahead of The Netherlands’ Marianne Vos of WaowDeals Pro Cycling, clocking a time of 4:08:06 for the 145km stage from Rushden to Daventry.

She now leads the overall standings with a time of 7:22:22.

Great Britain’s Danielle Rowe, who finished fourth today, is 15 seconds behind in second place.

Three-time world road race champion Vos is a further second back in third.

Finishing third today was Luxembourg’s Christine Majerus of Boels Dolmans Cycling Team.

Stage one winner Jolien D'hoore of Belgium finished 9:29 down on Rivera and the Mitchelton-Scott rider has subsequently dropped to 85th place in the general classification.

Tomorrow's stage is a 151km-leg from Atherstone to Royal Leamington Spa.