Garnett hit Channing Frye in the midsection as Frye attempted a 3-point shot. Garnett was given one technical for that foul and picked up another for his continued complaints with the officials.
After Garnett left, the remainder of the Boston starters were taken out of the game and the Celtics merely went through the motions for the closing minutes.
Gortat's points and rebounds were both season highs and helped the Suns end a three-game losing streak. Vince Carter added 17 points for the Suns and Steve Nash had 13.
Garnett led Boston with 18 points. Boston made only 34 percent of its shots from the field and hit only 2-of-18 from 3-point range.