Jaylen Brown scored 33 points and grabbed 10 rebounds while Derrick White added a season-high 27 points as Boston improved to 10-8.
Cunningham’s game-high 42 points were not enough for Detroit, which fell to 15-3 in a setback for their NBA Cup hopes as well.
The Pistons missed out on a club-record 14th consecutive victory, instead sharing the team-high 13-game win streak mark with the 1989-90 and 2003-04 squads that won NBA titles.
Detroit’s loss left Orlando alone atop East Group B in the NBA Cup at 3-0 with a showdown for the title and a playoff spot against the Magic coming Friday.
Anfernee Simons sank two free throws to give Boston a 115-112 lead with 6.3 seconds remaining.
Cunningham, the NBA’s top fourth-quarter scorer, was fouled just over mid-court and hurled the ball at the basket, referees giving him three free throws and a chance to level the game.
Cunningham made the first two but missed the third as the Boston crowd roared. Boston’s Payton Pritchard sank two final free throws and a bad pass by Jalen Durden denied Detroit a last shot at forcing overtime.
Wednesday’s games were in the NBA Cup mid-season tournament, which completes group stage play Friday.
Toronto has clinched the East Group A crown and the Los Angeles Lakers have taken the West Group B title.
Three group winners and a wildcard team from each conference will advance to the knockout stage, which starts on December 9. (AFP)
