About five minutes into the University of Manitoba choir's journey from Stockholm's Arlanda airport towards the town of Sundsvall, about 350 kilometres (200 miles) north of the capital, the bus starting swerving uncontrollably on the highway.
At that point, choir leader Elroy Friesen noticed the driver had fallen over the wheel, he told the local paper, Sundsvall Tidning.
"I threw myself forward and put the gear stick in what I thought was neutral. Then I hit the brakes," he said.
The bus eventually stopped, and none of the 32 passengers were hurt.
Passengers then pulled the driver out of the bus, with one choir member performing resuscitation and giving him mouth to mouth.
An ambulance arrived shortly after and he survived.
"Maybe it's a gift that I have to react instinctively instead of being passive. I'm surprised that no one was injured and that we did not crash into other cars," Friesen said.
The choir's tour continued as planned.