The Longhorns (3-2) went up by 18 points in the first half and coasted in the last 20 minutes, shooting 50 percent for the game.
Mississippi State (1-4) made one-third of its shots (17 of 51), improving in the second half after making only five field goals in the first.
Julien Lewis scored 13 of his 15 points in the first half. Cameron Ridley had eight points and 12 rebounds.
Roquez Johnson led the Bulldogs with 18 points, starting after limping off the court with help in the second half of Tuesday's loss to Marquette.
Texas took a 10-point lead midway through the first half, scoring eight straight points starting with a dunk from Cameron Ridley and finishing with a 3-pointer from Ioannis Papapetrou. Less than two minutes later, Prince Ibeh blocked a layup attempt from Trivante Bloodman, leading to a transition dunk for Lewis. The Longhorns took a 17-point lead with just under five minutes in the half on a 3-pointer from Demarcus Holland.
Mississippi State made no field goals in the half after Gavin Ware hit a jumper with 9:38 left. Its best run all game was seven straight points from free throws.
The Texas players took turns on personal scoring runs in the second half. McClellan scored eight straight for his team during a roughly two minute span, then Ridley scored six points during an 11-2 run in the middle of the half.
The matchup was the first time the teams had met since 2002, when sixth-seeded Texas upset third-seeded MSU in the NCAA tournament to reach the Sweet 16.
Each team lost its first two games in the eight-team tournament to set up the game for seventh place. Texas lost in a surprising 13-point blowout Monday night to Division II Chaminade, then lost Tuesday in overtime to USC. Mississippi State wasn't close in either of its first two games in Hawaii against No. 9 North Carolina and Marquette. It lost by a combined 73 points.
Oskar Garcia can be reached on Twitter at http://twitter.com/oskargarcia.