Jason Kidd's 3-pointer with 3.5 seconds to play put Dallas ahead as the Mavericks scored the last 10 points in a 101-97 NBA victory over Boston on Friday.
The Mavericks stretched their win streak to seven games and improved to 34-15, second in the Western Conference, while the Celtics slumped to 37-12, second overall to San Antonio.
"(I'm) not a shooter so they're going to give (me) the shot," said Kidd, best known for his assists.
Boston led 97-96 when Kidd sank his critical 3-pointer and German standout Dirk Nowitzki, who assisted on Kidd's key shot and scored a game-high 29 points for Dallas, added two free throws to create the final margin.
"The play was all over the place. I was just lucky to get the ball out to him," Nowitzki said. "That he made that shot is amazing."
Ray Allen, who led the Celtics with 24 points, missed a 3-pointer at the final buzzer and after rushing past Kidd on defense on the pivotal shot could only marvel at the Dallas veteran's effort.
"He's proven over his career that he can knock the 3-ball down," Allen said. "For most of his career, he hasn't been given the credit for being able to shoot because he's been able to do so many other things well.
"He has always had the stigma that he was flashy, but he was very effective."
It was Boston's fourth loss in 26 home games. The Celtics seized a 97-91 lead on a Kendrick Perkins layup with 2:42 to play but the hosts never scored again.
"We got shots that we wanted," Boston standout Paul Pierce said. "We just missed them."
Kidd scored 10 points and added nine assists for Dallas, which also had 17 points from Jason Terry plus 14 points and 15 rebounds by Tyson Chandler.
Kevin Garnett scored 12 of his 16 points for Boston in the first quarter while Perkins had 13 points and 12 rebounds.