Royce O'Neale tallied a double-double of his own with 14 points and 12 boards for the seventh-seeded Bears (22-10). Isaiah Austin tacked on 18 points for Baylor which faces second-seed Oklahoma in the quarterfinals.
Karviar Shepherd netted 19 points and Jarvis Ray and Kyan Anderson added 17 points apiece for TCU (9-22). Christian Gore chipped in 11 points.
Baylor got out to a 39-27 lead at halftime after shooting 51.9 percent from the floor, while limiting TCU to 37 percent in the opening period.
The Horned Frogs made things interesting in the second half, connecting on 53.8 percent from the field, but the Bears countered with a 56.7 percent effort to hold on.
Baylor outscored TCU 48-24 in the paint and owned a 39-22 edge on the glass.