Fredrik Kessiakoff (Astana) claimed victory in the stage seven time trial at the Tour de Suisse, while Rui Costa (Movistar) extended his overall lead.
Kessiakoff posted a time of 46 minutes 38 seconds to edge out home favourite Fabian Cancellara (RadioShack-Nissan) by just two seconds.
Cancellara's team-mate Maxime Monfort completed the top three after finishing 20 seconds back following the 34.3km test around Gossau.
Meanwhile, Costa gained time on his direct rivals in the general classification and now has a 50 second cushion over Roman Kreuziger (Astana) heading into the final two stages.
An impressive effort in the time trial helped Robert Gesink (Rabobank) climb all the way from 19th to third in the overall standings, 55 seconds adrift of Costa.
Cancellara, who recently returned from a lengthy injury lay-off, started early in the day and smashed the previous best time to set an intimidating benchmark.
But Kessiakoff passed through the first time check, situated at the top of a climb, comfortably faster and although he lost time on the subsequent flat and downhill he just managed to hold onto top spot.
After Monfort, Jeremy Roy (FDJ-BigMat), and Gesink slotted into the remaining top-five places, the best-placed overall riders took to the road to bring the stage to a conclusion.
But of the later runners only Costa managed to break the top 10, the performance meaning the Portuguese rider now enjoys a comfortable advantage ahead of two days in the mountains.