Jozy Altidore opened the scoring in the 67th minute and Toronto FC beat the Seattle Sounders 2-0 on Saturday in the MLS Cup to become the first Canadian champion in league history.
Toronto avenged a penalty-shootout loss to Seattle last year in the title game.
In the 67th, Sebastian Giovinco's pass from just inside the Seattle half helped Altidore split a pair of defenders. Altidore took a few steps to his left and fired the ball over goalkeeper Stefan Frei, setting off a wild celebration among the 30,584 fans that left BMO Field shaking.
Victor Vasquez made it 2-0 in injury time when from close range after substitute Armando Cooper's shot rebounded off the post.
Altidore scored in Toronto's 1-0 victory over Columbus Crew in the Eastern Conference final. He had 15 goals in the regular season, second on the team to Giovinco's 16. Altidore, who injured his right ankle minutes after scoring against the Crew, was replaced by Nick Hagglund in the 86th minute.
Toronto won the title in its 11th season, TFC did not reach the playoffs until 2015, the first season it avoided losing more often than it won.
Seattle was seeking to become the fourth back-to-back champion in league history, joining D.C. United (1996 and 1996), Houston (2006 and 2007) and the Los Angeles Galaxy (2011 and 2012).
Toronto outshot Seattle 22-7 and had 11 shots on target compared to two for the Sounders.
After going without a shot on goal in last year's MLS Cup, Seattle struggled to find the target in the opening 30 minutes Saturday, finally ending its dubious streak when defender Joevin Jones fired a tame effort into the arms of goalkeeper Alex Bono.
Toronto looked certain to open the scoring in the 11th minute when a long, accurate pass from Vasquez found Giovinco alone in the penalty box, but the 2015 MLS MVP's chip shot over a sliding Frei rolled wide.
In the 23rd minute, shortly after he blasted a 30-yard free kick directly into the Seattle wall, Giovinco got loose inside the 18-yard box and unleashed a hard, left-footed shot that Frei managed to palm over for a corner.
Toronto came close again in the 41st minute when Vasquez blasted a low shot across goal from outside the penalty box, but Frei dove to his right to push the ball to safety.
Jones was fortunate not to put the ball into his own net when he cleared Justin Morrow's shot along the goal line just before halftime. The Trinidadian defender, who is set to move to Germany's Darmstadt 98 next season, managed to steer the ball behind the goal for a corner.
Seattle had another scare in the 56th minute when defender Roman Torres, who scored the winning penalty in last year's final, nearly turned a cross into his own goal, but Frei scrambled over to make the save.