It marked Toronto's fifth straight victory and the largest comeback in franchise history (h/t TSN Sports' Josh Lewenberg).
Raptors fans showered Kyle Lowry, who led the Raptors with 32 points, with praise:
Toronto trailed by 30 points with 2:55 remaining in the third quarter. Lowry bucketed 20 of his 32 points in the fourth quarter, and the Raptors outscored the Mavs 47-21 in that final period.
Lowry also assisted on Chris Boucher's game-winning dunk with 25.8 seconds remaining in regulation:
Dallas was notably without reigning Rookie of the Year Luke Doncic, who sprained his right ankle on Dec. 14. Jalen Brunson, who has been starting at point guard in Doncic's place, led the Mavericks with 21 points.
The Raptors showed their championship grit as they were without forward Pascal Siakam (groin), guard Norman Powell (shoulder) and center Marc Gasol (hamstring). Toronto listed all three players as out indefinitely on Thursday.
Siakam has led the team in scoring with 25.1 points per game through 27 starts, while Powell was the hottest he's been all season, averaging 17.7 points in December.
Lowry compensated for the loss of Siakam's and Powell's scoring, but the defensive void left behind by Gasol was filled collectively:
The Raptors bench outscored Mavs reserves 48-20.
"Historically, I would say we've always been a team that fights," Toronto head coach Nick Nurse told reporters postgame. "We hardly ever mail it in. That's a good quality to have."
Nurse added he has "never seen anything like" Lowry's fourth-quarter performance.
The NBA hadn't seen anything like the Raptors' comeback since 2009:
According to Eric Smith, the largest comeback in franchise history prior to Sunday's triumph involved closing a 25-point deficit against the Detroit Pistons on Dec. 11, 2010.
Toronto improved to 21-8 with the win, tied with the Miami Heat for third in the Eastern Conference, while the Mavericks dropped to 19-10.
The Raptors have proved so far this season they won't be an easy out despite reigning NBA Finals MVP Kawhi Leonard choosing to depart for the Los Angeles Clippers in free agency. Sunday's performance was a statement that the defending champions are still the defending champions without him.