Running in a driving downpour in front of an enthusiastic but drenched crowd, Bolt splashed home in 10 seconds flat, well off his world record 9.69 set at last summer's Beijing Olympics.
After two false starts, Bolt trailed badly out of the blocks but rocketed away from the field after 50 metres to cross nearly 10 metres clear of American Shawn Crawford, silver medallist behind the Jamaican in the 200 metres at the Beijing Olympics.
"It (the false starts) threw me off a little bit but not much," Bolt told reporters. "I've been there before.
"Athletes have good days and bad days. I guess I can put this down as a bad ... I definitely enjoyed it though; I always enjoy it when I run."
Crawford, who won 200m gold at the 2004 Athens Games, ran 10.25 to nose out compatriot Ivory Williams on 10.28.
Bolt lit up a miserable night for the near capacity crowd of 5,835, some paying a hefty $250 to catch a glimpse of the man who claimed gold in the 100 and 200 metres in world-record times at Beijing, then helped the Jamaican 4x100m relay team to another gold medal.
Lured to the Festival of Excellence by a reported $250,000 appearance fee, Bolt was happy to get through the dangerous conditions and leave Toronto unscathed as he continues his build-up to this summer's world championships in Berlin.
"I felt good but I could have done a little better," said Bolt, who set another world best in a 150m street race in similar tricky conditions in Manchester last month.
"But it's alright, I got through injury-free and that's a good thing."
The 22-year-old Jamaican blew kisses at the crowd before his race, then ran a couple of victory laps around the Varsity stadium after, trailed by a large group of school children and huffing body guards.
Bolt is next scheduled to race on June 17 at the Ostrava Grand Prix in the Czech Republic.