Maybe Kevin Garnett  is right. Maybe the Celtics  should play the theme from Superman every time Paul Pierce  steps on the court. On a bum right knee, or at least very ‘ginger’ as Pierce himself said, the Celtics captain made 13 of his 26 shots and totaled a season-high 39 points to lead the Celtics to a 115-109 overtime win against the Toronto Raptors  Monday night at TD Banknorth Garden . With the Celtics already missing starting center Kendrick Perkins  with a bad left shoulder and Tony Allen  in a protective boot with a sprained right ankle, Pierce picked it up a notch for the entire game, even when Andrea Bargnani hit a three with one second remaining. Pierce did have a supporting cast, as Kevin Garnett scored 20, Ray Allen  12 and Brian Scalabrine , playing for Perkins, chipped in with 11, including three three-pointers.