The Celtics handed the Cleveland Cavaliers their 1st loss of the regular season with a (120-117) win at TD Garden Tuesday night.  The Celtics improve their record to 12-3 with the win.  The Celtics are also 1-1 in NBA Cup Pool Play.  Jayson Tatum led the Celtics with 33.  Tatum also had 12 rebounds and 7 assists. Donovan Mitchell scored a game-high 35 in the Cavs 1st loss of the regular season.  The Celtics shot 54% from behind the 3-point line and hit 12 more 3's then the Cavaliers.  Al Horford hit 4 3's and scored 20. Derrick White also knocked down 4 3's and scored 19. ----- Knocking Down 3's: The Celtics hit 9 3's in the 2nd Quarter, including Jayson Tatum's on the Celtics final possession before the Half.  The Celtics had 14 3's in the 1st 24 minutes.  Payton Pritchard knocked down 2 from distance.  -----