Seventh-seeded Saint Mary’s rallied from a sluggish offensive start and a second-half deficit of 12 points to upend No. 10 seed Vanderbilt 59-56 in the first round of NCAA Tournament East Region play on Friday in Cleveland.

The Gaels (29-5) fell behind 39-27 just before the first media timeout of the second half when Vanderbilt’s Tyler Tanner connected on a 3-pointer. Saint Mary’s chipped away at the deficit over the ensuing eight minutes, however, embarking on a 16-4 run.

That set up a tightly contested final eight minutes, during which Saint Mary’s led most of the way but never by more than six points.

The Commodores (20-13) got 3-pointers from Devin McGlockton and Tyler Nickel in the final two minutes, bringing Vanderbilt to within a basket. Saint Mary’s Luke Barrett missed a jumper with 30 seconds remaining, but teammate Mitchell Saxen came up with the offensive rebound in traffic — one of his 11 boards on the day — and drew a foul.

Saxen made 1 of 2 free throws, giving Vanderbilt a final possession to force overtime. Jason Edwards missed a contested step-back 3-point attempt, and McGlockton’s clean look off the offensive rebound was no good.

Jordan Ross skyed for the rebound to seal Saint Mary’s third first-round win in the last four years.

Ross led the Gaels with 15 points, while both Saxen and Barrett finished with double-doubles. Each scored 12 points, with Barrett grabbing 10 rebounds. Augustas Marciulionis scored 14 points, and he and Ross went a combined 4-of-6 from 3-point range in the second half, a dramatic departure from the first half when the Gaels shot a dismal 2-of-16 from outside.

Vanderbilt went 8-of-26 from 3-point range on the day. Edwards, who finished with a game-high 18 points, finished just 2-of-9 from beyond the arc.

The Commodores committed only four turnovers, but their shooting woes — going 22-of-55 from the floor overall — contributed to a 41-28 rebounding gap in Saint Mary’s favor.