Justice also had 10 rebounds and the Broncos had a 39-24 advantage on the boards against a team that came in grabbing 48 misses a game, 17 on the offensive end.
Santa Clara will play Fresno State on Wednesday while TCU faces Pepperdine.
TCU (3-1) was only allowing 54 points a game while Santa Clara shot 53.8% over its first four games.
TCU's only lead was an opening free throw and the Horned Frogs tied the game at four. The Broncos kept a slender lead until Santa Clara went on a 12-0 run that closed the first half for a 43-29 lead.
Williams had 12 points for the half, 10 in the final 4 1/2 minutes and four in the closing run. The Broncos closed the half making 7 of 8 shots.
Santa Clara shot 60% (18 of 30) while TCU shot 37% (11 of 30).
The Broncs followed that 10-point run by scoring the first 14 of the second half for a 57-29 lead. Pipes had two 3s and Giordo Williams and Justice also connected from distance. They made 6 of 7 shots.
TCU put together a 12-0 run as Santa Clara had a string of turnovers but only got within 16.