The angry Ferrari driver, belatedly arriving to attend the podium after complaining to the stewards immediately after Sunday's race, moved the P2 sign to winner Lewis Hamilton's Mercedes car in parc ferme, and took the P1 marker for himself.
Vettel's show of defiance came after a controversial decision to hand the German a five-second time penalty cost him what looked set to be a first race win of the Formula One season in Montreal, forcing him to settle for second place.
The Ferrari fans in attendance were loving it at Circuit Gilles Villeneuve when Vettel placed the P1 sign where his car should have been parked and he gave the crowd a cheeky grin and a wave as he marched up to join Hamilton and team-mate Charles Leclerc, who finished third on the podium.
The decisive moment had come on lap 48 when Vettel, who was in control despite pressure from Hamilton after starting from pole position for the first time in 17 races, ran wide at turn four and re-joined the track via the grass, only just avoiding pushing the Briton into the wall.
Race stewards ruled against Vettel and handed him a time penalty for an unsafe re-entry, deeming Hamilton had needed to take evasive action.
It meant Hamilton just had to stay fewer than five seconds behind to claim the win, which he duly did – earning his fifth win of the season and Mercedes' seventh in a row.
"They are stealing the race from us," protested Vettel after learning of the verdict, which meant he did not win despite being the first man to the chequered flag.
Hamilton briefly allowed Vettel to share the top step of the podium with him, in acknowledgement of the Ferrari man's performance.