The 29-year-old Bell overtook 2011 world championship road race silver medallist Matthew Goss of Australia just before the finish line to win for the Spidertech team.
The Canadian national team's Remi Pelletier-Roy of Longueuil, Que., was third ahead of Australian Michael Matthews of the Radobank squad.
"It was four really fast guys," said Bell. "I just came from the Olympics and I knew I had some power and I just had to lay it on the track."
Spidertech boss Steve Bauer brought Bell in specifically to race the sprint. He will not take part in the UCI World Tour event on Friday.
"Last year I screwed up in the first round of this race, so I was on a bit of a mission," said Bell, who was eighth in the men's omnium at the London Games.
The sprint is an unofficial event, but it drew large crowd as riders, going off four at a time, went slowly 500 metres up the road, made a u-turn, then dashed back to the start-finish line.
"It's a great event, but I don't think it's ideal if you have to race the next day," said Goss, who will be supporting leader Simon Gerrans in the main race for the Orica Greededge squad. "But it's great fun."