The Swiss rider gave RadioShack a boost by claiming the home nation’s fourth stage win so far this tour, pulling away from Team Sky’s Australian Matthew Hayman and Alexandr Kolobnev of Katusha to come home in four hours, 23 minutes and 53 seconds.
Bert Grabosch faded in the final metres to come fourth.
“It is a big victory for me,” Rast said. “I have ridden the Tour de Suisse for 10 years, this is near my home and so it is very big for me.”
BMC’s Mathias Frank retained his overall lead, 23 seconds ahead of Roman Kreuziger of Saxo-Tinkoff.
The leading four managed to get away one third into the 186.1km ride from Lueggern and at one point built up a 14-minute lead.
The peloton was happy to keep its distance, finishing 10:43 back with the front four having no impact on the General Classification.
The final climb took a lot out of the breakaway group, but Rast had the most left in the tank.
It was a good thing he did, as he is the weakest sprinter of the quartet, able to pull away with 1km left to leave Hayman and Russia’s Kolobnev to slug it out for second.
1. Gregory Rast (Switzerland / RadioShack) 4:23:53"
2. Mathew Hayman (Australia / Team Sky) ST
3. Alexandr Kolobnev (Russia / Katusha)
4. Bert Grabsch (Germany / Omega Pharma - Quick-Step)
5. Peter Sagan (Slovakia / Cannondale) +10:43"
6. John Degenkolb (Germany / Argos)
7. Arnaud Demare (France / FDJ)
8. Ben Swift (Britain / Team Sky)
9. Davide Cimolai (Italy / Lampre)
10. Tosh Van der Sande (Belgium / Lotto)
1. Mathias Frank (Switzerland / BMC Racing) 20:31:05"
2. Roman Kreuziger (Czech Republic / Saxo - Tinkoff) +23"
3. Rui Costa (Portugal / Movistar) +35"
4. Thibaut Pinot (France / FDJ) +57"
5. Bauke Mollema (Netherlands / Blanco) +1:08"
6. Daniel Martin (Ireland / Garmin) +1:23"
7. Jean-Christophe Peraud (France / AG2R) +1:28"
8. Tejay Van Garderen (U.S. / BMC Racing) +1:39"
9. Cameron Meyer (Australia / Orica) +1:42"
10. Alexandr Dyachenko (Kazakhstan / Astana) +1:59"
- Sports & Recreation
- Alexandr Kolobnev
- Gregory Rast
- Mathias Frank
- Team Sky
- Mathew Hayman