The two clashed on the run down to Ste Devote, with Verstappen hitting the rear of Grosjean's Lotus approaching the braking zone, with the Toro Rosso spearing in to the barrier at high-speed having broken its front left suspension. While Verstappen accused Grosjean of brake testing him in the incident, the stewards disagreed and penalised the Toro Rosso driver.
Having investigated the collision, the stewards blamed Verstappen for causing the incident and handed him a drop of five grid positions for the Canadian Grand Prix. Verstappen was also given two penalty points.
Grosjean had been running tenth at the time of the incident, but eventually finished outside the points in Monaco while team-mate Pastor Maldonado also retired early on following contact with Verstappen.
Click here for a gallery of Max Verstappen's crash with Romain Grosjean during the Monaco Grand Prix