Lewis Hamilton maintained Mercedes' record winning start to a season on Sunday when he was handed a controversial victory, courtesy of a disputed stewards' decision to penalise Sebastian Vettel, at the Canadian Grand Prix.
The defending five-time world champion overall leader came home second on the track behind Vettel of Ferrari, but was declared the winner because of a five-second penalty for a racing infringement by the German.
Vettel ran off and re-joined across a strip of grass on lap 50, forcing a charging Hamilton off-track towards a wall. The Briton braked to withdraw from his challenge to take the lead, prompting a race stewards' inquiry, which resulted in the time penalty.
"Where could I go?" protested Vettel. "They're stealing the race from us. No, no, no, not like that," he repeated on his slow-down lap as Hamilton celebrated. "If there wasn't a wall, I would have gone past him," said the Briton.
In a bizarre sequence, Vettel at first refused to attend the post-race interviews and stormed away to the Ferrari motor home before, after persuasion by the Italian team, he returned for the podium ceremonies.
As he did so, however, he walked to the parc ferme and moved the numbers used to mark the finishing order - shifting the number one to the blank space for his car, two for Hamilton's Mercedes and three for Charles Leclerc.
It was Hamilton's record seventh victory in Canada, and the 78th of his career, and extended Mercedes' season-opening run to seven successive wins.
Vettel ended up classified second ahead of his Ferrari team-mate Leclerc, fourth-placed Valtteri Bottas in the second Mercedes, Max Verstappen of Red Bull and Daniel Ricciardo of Renault.
Nico Hulkenberg finished seventh in the second Renault ahead of Pierre Gasly of Red Bull, home hero Lance Stroll of Racing Point and Daniil Kvyat of Toro Rosso.
Hamilton had problems before the start. A hydraulics leak, discovered in the morning, required two hours of stripping down and the repair of his power unit and then a slow getaway for the formation lap created more alarm.
On a hot afternoon on the Isle Notre-Dame, with temperatures of 50 and 29 degrees Celsius for track and air, tyre wear was a key factor, which encouraged Hamilton to bide his time.
On lap 25, Vettel pitted from the lead for hard tyres and re-joined third leaving Hamilton to push on his worn rubber as Vettel clocked fastest lap behind new leader Leclerc.
Vettel led again by 2.3sec ahead of Hamilton with Verstappen third, 10sec adrift. On his hard tyres, Hamilton looked revitalised as he closed in on the German.
A mistake by Vettel after 49 laps, when he twitched under braking at the first chicane, forced him to cut across a strip of grass before rejoining narrowly ahead of Hamilton. The Englishman saw a gap, but was squeezed out towards a wall.
The race stewards announced an investigation into the incident which, on lap 58, resulted in a five-second penalty for "unsafe re-entry forcing another driver off the track."