DeMar DeRozan netted 20 points and Rudy Gay added 19 points and six rebounds in the Toronto Raptors' 101-98 win over the short-handed Chicago Bulls.
Kyle Lowry finished with 13 points and 10 assists for the Raptors, who have won three of their last four games.
"The guys came up and showed some fight," Raptors head coach Dwane Casey said.
Jimmy Butler registered 28 points and seven boards for Chicago, which played without Joakim Noah, Luol Deng and Taj Gibson.
The Bulls fell three games behind the Brooklyn Nets for the fourth seed in the Eastern Conference and saw its lead for the No. 5 seed trimmed to a half-game of the Atlanta Hawks.
Back-to-back buckets by Amir Johnson and Gay vaulted the Raptors to a 99-90 cushion with 1:38 left before Chicago netted the next seven to make it a game.
Boozer hit a layup before Nate Robinson hit a triple, and after Gay missed a bank shot, Boozer sunk two free throws to pull the Bulls within 99-97 with 16.8 ticks left.
DeRozan, though, made a pair of foul shots at the other end with 13.4 seconds remaining. Robinson was then fouled and made the first free throw before missing the second. A jump ball was called between Boozer and Gay following the miss. Boozer won the tip, but Robinson's 41-footer for the tie was off the mark with less than a second to play.
"We have to be a lot tough mentally," Bulls head coach Tom Thibodeau said.
The Raptors led 31-22 after a quarter of play, 54-50 at the break and 81-68 heading into the final frame.
The Bulls held a 21-6 advantage in second-chance points ... Toronto led by as many as 16 ... The Bulls were 10-of-17 from beyond the arc ... Boozer recorded 19 points and 11 boards.