By Lap 30, nearly everyone on the circuit aside from the top three had stopped for fresh Pirellis. This initially changed with Raikkonen entering the pits on Lap 33, followed by both Bottas and Vettel four laps later. The rivals maintained their battle at the front of the field, though the Ferrari driver was able to display his advantage on the supersoft compound.
Varying track temperatures began to factor in as they registered at 105 degrees Fahrenheit before the start, dropping by 10 degrees at the halfway point. Still, drivers had to manage their brakes as Montreal upheld its reputation as the most demanding braking circuit on the schedule.
Fernando Alonso had been piloting his McLaren-Renault exceptionally well to Lap 42 where, despite his perseverance, he retired due to an exhaust failure. Unfortunately for Fernando, his 300th Grand Prix weekend was capped off with an all too familiar retirement at the Circuit Gilles Villeneuve.
Panning back to the No. 5 entry from Maranello, Vettel was being outpaced by Bottas although he held the lead through a tough three-lap stretch where his Mercedes competitor was lapping three seconds quicker around the demanding course. Just as Bottas' chances at a P1 spot began to show, he ran off-track and lost the time he had gained in the last handful of laps and sank down to a surely-unsatisfying second place.
Source : http://www.thedrive.com/accelerator/21437/sebastian-vettel-dominates-2018-canadian-grand-prix-from-pole-to-take-championship-lead