Oklahoma State's Marshall Moses (33) drives the ball around Iowa State's Jamie Vanderbeken (23) in the second half of an NCAA college basketball game at the Big 12 Conference men's tournament in Oklahoma City, Wednesday, March 11, 2009.

Marshall Moses matched his career high with 18 points and provided a much-needed inside threat as Oklahoma State held off scrappy Iowa State 81-67 on Wednesday night in the first round of the Big 12 Conference tournament.

Obi Muonelo exited the bench to also score 18 points for Oklahoma State (21-10). The win, the seventh in eight games for a team hoping for an NCAA tournament berth, propelled the Cowboys into a quarterfinal showdown against second-seeded Oklahoma.

Oklahoma State lost 82-78 to No. 6 Oklahoma in the regular-season finale on Saturday. It will be only the third time the Bedlam rivals will have played in Oklahoma City in a series spanning 102 years and the first time since March 1942.

Craig Brackins had 23 points and 12 rebounds for his 15th double-double of the season for Iowa State (15-17), which hasn’t won a Big 12 tournament game since 2005.