Burghardt, who took the fifth stage on Wednesday, finished on his own some 55 seconds ahead of Oscar Freire, Greg van Avermaet and Manuel Quinziato, three of 15 riders who took off in a morning breakaway.
Dutchman Robert Gesink (Rabobank), who finished in the peloton five minutes behind, keeps the leader’s yellow jersey. He is 29 seconds ahead of Spaniard Rigoberto Uran and 36 in front of BMC’s Steve Morabito.
Frank Schleck is a further two seconds back with Lance Armstrong in seventh place, 55 seconds behind the leader.
Burghardt, a stage winner in the Tour de France two years ago, made his move 60km from home when he broke away from the leading group, which had itself gone clear 62km into the race.
They had built up a five-minute lead over the peloton before Burghardt’s decisive escape. The eighth stage on Saturday sees the peloton travel the 172km between Wetzikon and Liestal. It ends with a time-trial on Sunday.
Top-10, Stage 7
- 1. Marcus BURGHARDT (GER) BMC Racing Team in 4:52:02
- 2. Oscar FREIRE GOMEZ (ESP) Rabobank Cycling Team at 1:01
- 3. Greg VAN AVERMAET (BEL) Omega Pharma-Lotto at 1:01
- 4. Manuel QUINZIATO (ITA) Liquigas-Doimo at 1:01
- 5. Luis Leon SANCHEZ GIL (ESP) Caisse D’Epargne at 1:08
- 6. Mathias FRANK (SUI) BMC Racing Team at 1:08
- 7. Juan Antonio FLECHA GIANNONI (ESP) Team Sky at 3:24
- 8. Matti BRESCHEL (DEN) Team Saxo Bank at 3:28
- 9. Michal GOLAS (POL) Vacansoleil Pro Cycling Team at 3:28
- 10. Jurgen VAN DE WALLE (BEL) Quick Step at 3:28
Overall Standings, after Stage 7
- 1. Robert GESINK (Netherlands) Rabobank Cycling Team in 30:15:59
- 2. Rigoberto URAN URAN (Colombia) Caisse D’Epargne at 29
- 3. Steve MORABITO (Switzerland) BMC Racing Team at 36
- 4. Frank SCHLECK (Luxembourg) Team Saxo Bank at 38
- 5. Joaquin RODRIGUEZ OLIVER (Spain) Team Katusha at 42
- 6. Matteo CARRARA (Italy) Vacansoleil Pro Cycling Team at 54
- 7. Lance ARMSTRONG (United States) Team RadioShack at 55
- 8. Oliver ZAUGG (Switzerland) Liquigas-Doimo at 1:01
- 9. Jakob FUGLSANG (Denmark) Team Saxo Bank at 1:17
- 10. Thomas LÖVKVIST (Sweden) Team Sky at 1:38