A spectator taping the event caught the horrific moment on her smart phone.
The video shows a car pulling out of a parking lot, right onto the bike race course. The fast-moving cyclist hit the driver side of the car and was thrown onto the hood, smashing the windshield.
The ambulance arrived 10 minutes later, and police say the woman is expected to recover from her injuries.
Spectators blame Quebec provincial police officers who were providing security on the course. Police say they are aware of the video and will take it into consideration along with testimony from witnesses and other factors.
About 600 people were racing in the Lac-Beauport triathlon.