Betts lay-up gave the Bulls a 64-62 lead with 4:41 left to play and sparked a late game-clinching 14-4 run for Buffalo.
Betts also had seven rebounds, while Greg Gamble scored 15 points. Max Boudreau scored 9 of his 11 points in the second half comeback.
Andy Robinson -- who scored 13 points and grabbed four rebounds -- gave Buffalo (3-2) its first lead with a slam dunk with 9:49 left after trailing by as many as 14.
Temple's (3-2) Dionte Christmas scored a game-high 25 points and had six rebounds and five assists.
Temple led 39-33 at halftime. The Owls shot 29-55 for the game, but went just 8-of-22 on three-point attempts.