The horse and carriage were heading west down Fisgard Street around 2:15 p.m. PT when, according to witnesses, a tour bus bumped the horse, causing it to buck and throw two people from the carriage.
The horse then took off down Store Street, turning onto Wharf Street with a screaming passenger still in the carriage, according to Victoria police.
It struck a car, tossing the remaining passenger onto the street near the intersection with Fort Street.
That's when Eric Backhouse was riding by on his bike and decided to give chase.
"I don't even know why I did it. I just thought this isn't going to be good and I just took off after him.... He wasn't even going that fast, but by the time I got to him, I knew that he was pretty agitated," said Backhouse.
"I guess my instinct took over at that point and I just held up my hand and said, 'Whoa. Whoa,' and thank goodness he slowed down."
Police are investigating what led up to the incident, but say that remarkably, no one appeared to be seriously injured.