Ireland’s Dan Martin finished seventh on the third stage of the Tour of Switzerland and occupies the same spot in the general classification after the 203.3-kilometre run from Montreux to Meiringen.
Compatriot Nicolas Roche finished 16th on the stage and is 20th overall.
Garmin-Sharp’s Martin finished 46 seconds behind stage winner Peter Sagan, while Roche (Team Saxo-Tinkoff) was one minute and 47 seconds off the leader.
Mathias Frank took the overall lead, but a crash threatened to derail Ryder Hesjedal's Tour de France aspirations.
Cannondale rider Sagan, the green jersey winner on last year's Tour de France, signalled his strength ahead of this year's showpiece as he came out on top in the race for the line after being part of a four-strong group that went clear on the final descent of the day.
Movistar's Rui Costa secured second place with Roman Kreuziger (Saxo-Tinkoff) in third, while fourth place was enough to put BMC rider Frank at the head of the overall standings.
But it proved to be a nightmare day for Canadian Hesjedal, who has been targeting a podium finish on the Tour de France.
The Garmin rider had started the day second in general classification, but he ended it on his way to a local hospital to be evaluated after his crash.
Frank now leads Kreuziger by 25 seconds, with Costa 10 seconds further back.
The Garmin-Sharp team later released a statement on Hesjedal's condition, which read: "Ryder Hesjedal crashed during today's stage at the Tour de Suisse, suffering a heavy blow to the neck and head.
"He was immediately transported to a local hospital for evaluation. Hesjedal suffered multiple, severe contusions and abrasions to the right wrist, hip and knee and left shoulder, elbow and knee.
"Preliminary CTs show no fractures and no neurological pathologies. He will remain under close observation by team medical staff.
"Hesjedal's health is the team's priority - depending on how his recovery progresses team medical staff as of now hopes he may be able to train in a few days time, although this will depend on his recovery."
Leading positions after Stage 3 (Montreux - Meiringen, 203.3km):
1 Peter Sagan (Svk) Cannondale Pro Cycling 4hrs 46mins 27secs
2 Rui Alberto Faria da Costa (Por) Movistar Team at same time
3 Roman Kreuziger (Cze) Team Saxo-Tinkoff at same time
4 Mathias Frank (Swi) BMC Racing Team at same time
5 Bauke Mollema (Ned) Blanco Pro Cycling Team at 39secs
6 Giovanni Visconti (Ita) Movistar Team at 46
7 Daniel Martin (Irl) Garmin-Sharp at same time
8 Thibaut Pinot (Fra) FDJ at same time
9 Tanel Kangert (Est) Astana Pro Team at same time
10 Jean-Christophe Peraud (Fra) AG2R La Mondiale at same time
General classification after Stage 3:
1 Mathias Frank (Swi) BMC Racing Team 7hrs 39mins 38secs
2 Roman Kreuziger (Cze) Team Saxo-Tinkoff at 23secs
3 Rui Alberto Faria da Costa (Por) Movistar Team at 35
4 Giovanni Visconti (Ita) Movistar Team at 53
5 Thibaut Pinot (Fra) FDJ at 57
6 Bauke Mollema (Ned) Blanco Pro Cycling Team at 1min 08secs
7 Daniel Martin (Irl) Garmin-Sharp at 1.23
8 Tanel Kangert (Est) Astana Pro Team at 1.26
9 Jean-Christophe Peraud (Fra) AG2R La Mondiale at 1.28
10 Tejay van Garderen (USA) BMC Racing Team at 1.39