Kevin Foster netted 24 points, including the go-ahead 3-pointer with 1:13 remaining, to lift Santa Clara over George Mason, 80-77, to take the College Basketball Invitational title in the third and final game of the series.
Patrick Holloway's potentially game-tying left wing triple with a second remaining was off the mark.
Marc Trasolini tallied 20 points and six rebounds, while Evan Roquemore added 19 points, six assists, four boards and three steals for Santa Clara (26-12), which finished fourth in the West Coast Conference.
Sherrod Wright led George Mason (22-16) with 24 points and 10 rebounds.
After Foster's triple gave the Broncos a 75-73 lead, Bryon Allen and Foster missed treys before Vertrail Vaughns split a pair of free throws with 25 ticks remaining to pull the Patriots within one.
Four foul shots by Roquemore, sandwiched around an Allen layup, made it 79-76 with nine seconds left. Santa Clara elected to foul instead of defending the 3-pointer, but Wright missed the first free throw before sinking the second. Foster split a pair to make it 80-77 before Holloway missed his triple at the buzzer.
The Patriots took a 37-33 cushion into the break.