Waldow made a pair of free throws with 1:28 left to give the Gaels a 48-44 lead. After Taylor David made the second of two free throws for Pacific, Saint Mary's turned it over and Gabriel Aguirre made a layup, but couldn't convert the three-point play, with 32 seconds to go.
Eric Thompson grabbed the offensive rebound off Aguirre's miss, but T.J. Wallace missed a layup and Waldow secured the board. Aguirre was called for a foul and then hit with a technical after the play. Waldow made 1 of 2 and Aaron Bright made both technical free throws, giving Saint Mary's a four-point lead and the ball.
Bright was immediately fouled after the inbounds pass and two more free throws put the game out of reach.
Saint Mary's (13-3, 5-0) shot a season-low 32.7 percent, but made 17 of 21 (81 percent) free throws. Pacific (9-8, 1-4) was 8 of 18 from the stripe.