CHARLOTTE , N.C.- Twenty-one second half points from Donald Sims broke open a close game as Appalachian State University men's basketball won a 71-61 decision against The Citadel in the Southern Conference Tournament's quarterfinal round.

Sims finished the night with 30 points on 10-of-19 shooting, four rebounds and a 7-of-7 mark from the free throw line. He sank three treys on the evening to take over first place on the program's single-season three-point list.

Both teams struggled from the field in the first half, shooting just 34 percent each before halftime. Each team was more proficient from outside the arc than from inside in the first half as well, and neither team led by more than six points before the intermission. The Bulldogs (16-16) kept the pace in their favor with just a 27-24 deficit after 20 minutes.

After the break, the Mountaineers (21-12) heated up from the field and extended the lead to 10 points over the first five minutes of the frame, behind five points from Sims and four from Isaac Butts.

The Citadel pulled back within four points almost immediately, but following a pair of Andre Williamson free throws, the Apps regained control for the final 12 minutes of the game. Williamson scored just two points in the game but grabbed four rebounds and swatted a block in 14 minutes off the bench.

The Mountaineers were 16-of-22 from the charity stripe in the game, including 10-of-13 in the final three minutes.

Kellen Brand scored 15 points on 7-of-13 shooting while Butts chipped in nine points in the second half to finish with 11 for the game, to go along with seven boards.

Zach Urbanus kept the Apps from running away with the game by knocking down four second-half threes. He led The Citadel with 15 points while Austin Dahn and Cameron Wells added 11 each.

Though Appalachian struggled shooting early on, the squad made 14-of-24 shots in the second half to end up at 44.6 percent on the night. The squad was also fundamentally sound, matching the team's season low of seven turnovers. ASU also owned a 42-25 advantage on the boards.

Josh Hunter led the rebounding attack with 10 on the night to accompany one point. The forward also dished out one of the team's season-low three assists on the night. The Cadets recorded 11 assists, led by four from Wells.

The Mountaineers boarded 28 of The Citadel's missed shots and gave up just three offensive rebounds to the South's fourth seed.

Appalachian moves on to Sunday's semifinal against the winner of Saturday's late game between College of Charleston and Chattanooga. The 8:30 p.m. contest will be televised regionally on SportSouth. Western Carolina and Wofford square off at 6 p.m.

Notes: With the win, Buzz Peterson moves to 9-3 in SoCon Tournament play ... The win is also Peterson's 100th at Appalachian, tying him for fifth on the program's career list with current CofC coach Bobby Cremins ... ASU is 7-1 against The Citadel in the tournament ... The Mountaineers advance to the semifinals for the first time since 2007, when the squad lost an 89-87 overtime contest to the Cougars ... Donald Sims' 30 points in the game tie him for third-most in a tournament game in ASU history (Junior Braswell vs. Marchall, 3/1/97) and move him within 22 points of ASU's single-season record (Billy Ross - 683, 1992-93).