Defoe, one of Toronto's marquee off-season signings, scored both of his team's goals in a 2-1 win against the Seattle Sounders to start TFC's Major League Soccer season.
It was Toronto's first win to open a season since 2009, and only the second in its seven-year existence.
"I thought the guys were magnificent in the first half when it came to their football and magnificent in the second half when it came to their desire and their character," said Toronto head coach Ryan Nelsen.
Defoe, who hadn't scored since Jan. 11 for former club Tottenham Hotspur in the English Premier League, needed just 24 minutes to secure the win for his new team.
He spoke earlier this week about his desire to perform well in case England coach Roy Hodgson was watching. With his two-goal performance on Saturday, Defoe has renewed hope for inclusion in England's squad for the 2014 World Cup in Brazil this summer.
"To score two goals on your debut, it's a dream," Defoe said. "The England thing is obviously going to be at the back of my mind."
After early pressure from the Sounders, Defoe made a run between two Seattle defenders in the 17th minute. Jonathan Osorio, on the ball in midfield, slipped a perfectly weighted pass through the gap, and Defoe nestled the ball into the goal.
Seven minutes later, Defoe picked up a loose ball after a Sounders giveaway near their own penalty area. He found space to cut to the right and fire another shot past goalkeeper Stefan Frei.
"The first goal was a great ball, and you just have to finish it off," Defoe said. "The second half, we showed great character because they put us under a lot of pressure. You've got to do that sometimes away from home."
Seattle began the second half as it did the first, pressuring Toronto's goal. Another big-name signing, Brazilian goalkeeper Julio Cesar, made his first important intervention in the 53rd minute.
He fell to his right and stuck out his left leg, deflecting a close-range shot from Obafemi Martins out for a corner kick.
However, the Sounders' pressure would eventually pay off. Seattle's own Designated Players, Martins and Clint Dempsey, combined down the right flank in the 68th minute, putting Dempsey in space on top of the penalty area.
The U.S. international took a settling touch with his left foot before slamming a right-footed shot low and to Cesar's left. The CenturyLink Field crowd of 38,441 came to life, and the Seattle attack continued to press.
Toronto's back line held, helped by several foul calls by referee Ioannis Stavrides close to its goal, despite dropping into a defensive shell for the last 15 minutes of the game.
Notably, Seattle substitute Kenny Cooper got behind the defence with five minutes remaining, but his central pass went wayward under pressure from Cesar rushing out of his goal. Osorio headed clear a tame Sounders corner kick in stoppage time, which effectively closed out the match.
"There's no doubt in my mind that as the season goes on, we'll continue to improve, and our football will be good," said Toronto midfielder Michael Bradley, another one of the club's big off-season signings . "Tonight was different. Tonight was about the spirit, the mentality and doing whatever it took to come away with three points."
Nelsen downplayed the result throughout his post-game talk with media, choosing instead to expound his desire for consistency over a long MLS season.
"We've got so much to improve on. We're not stupid," he said. "What I like about this team is their heart, their character, their desire — that they want to win. That's what you hope for. You build your house on that type of foundation."
Toronto (1-0) plays its first home game of the season on March 22 when it hosts D.C. United at BMO Field. Seattle (1-1) takes to the road for the first time the same day, playing the Montreal Impact.