The Bears squandered a 14-point first-half lead but went on a late 8-0 run to pull away. Baylor (27-7) now heads back to its home state to play No. 10 seed Saint Mary's in Houston in the South Regional semifinals.
Baylor struggled to beat Sam Houston State in the first round for its first NCAA tournament win since 1950, but the Bears arrived loose and confident against Old Dominion, using a barrage of early 3-pointers and alley-oops to take a double-digit lead.
Old Dominion (27-9) rallied and pulled ahead in the second half, but the Bears received a big lift from 7-footer Josh Lomers, who tied a career high with 14 points, 12 in the second half.