Gay also provided seven rebounds and five assists for the Grizzlies, who connected on 8-of-13 three-point tries en route to their third victory in four games.
Evan Turner led the Sixers with 27 points and seven assists.
Thaddeus Young chipped in with 23 and Jrue Holiday donated 18 points and 10 assists for Philadelphia.
Reindeer recovered after escaping from Santa during lighting ceremony
Selena Gomez drops F-bomb, walks off stage during Jingle Ball performance