DeCosey was 6 of 11 from the field, 4 of 7 from beyond the arc and 14 of 17 from the line. He added seven rebounds. Obi Enechioyia scored 13 points and Trey Lowe added 11 for Temple (12-8, 6-3 American).
Temple closed the first half with a 12-4 run and led 35-31 at the break.
The Owls' second-half lead reached 13 points twice, but USF got it to five, 61-56, after Nunez' layup with 2:30 left.
Devin Coleman responded with a 3-pointer on the next possession though, and Temple made 6 of 10 at the line down the stretch to hold off the Bulls.