SIOUX FALLS, S.D. -- Freshman Joe Rosga scored a career-high 25 on 9-of-11 shooting to help No. 6 seed Denver beat third-seeded Omaha 78-70 Sunday night in the Summit League tournament quarterfinals.

Rosga had 15 points in the first half as the Pioneers shot 62.5 percent and built a 19-point lead before going into the break with a 44-29 advantage.

Tre'Shawn Thurman scored nine, and Tra-Deon Hollins seven in a row, as Omaha (18-13) opened the second half with a 21-9 run to pull within three with 11 minutes to play.

Randy Reed's dunk with 6:39 left capped a 7-0 run and gave the Mavericks their first lead of the game, but Rosga scored six as Denver (16-14) responded with a 13-5 spurt that made it 72-65 with 1:19 to play.

The Pioneers will face No. 2 seed South Dakota State (24-7) in the semifinals Monday night.

Hollins led Omaha with 17 points, eight assists, seven steals and two blocks.

It was the third-lowest scoring output of the season for Omaha, which came in averaging 84.9 points per game (4th in Division I).