OKLAHOMA CITY – As Marshall Moses' fortunes have risen in recent weeks, so have those of the Oklahoma State Cowboys – so much so that an NCAA tournament bid now seems likely.

The sophomore forward matched his career high with 18 points and provided a much-needed inside presence, while Obi Muonelo exited the bench to also score 18 as an outside threat as Oklahoma State held off Iowa State 81-67 on Wednesday night in the first round of the Big 12 Conference tournament.

The win, the seventh in eight games for the Cowboys, propelled them into a quarterfinal showdown against second-seeded Oklahoma. Oklahoma State (21-10) 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 – and the first time since March 1942 – in a series spanning 102 years and 214 previous games.

"I think it definitely puts us in the NCAA tournament," Muonelo said of the win. "We have worked hard to get to this point and all year coach has been talking about how we want to work hard to get to the tournament and really just drive. That was our goal at the start of the year. I think this game definitely solidifies that."

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.

Brackins, a sophomore who could jump into the NBA after this season, became the fifth player in school history to reach the 1,000-point mark in two seasons, finishing with 1,011. Asked when he'll decide whether to stay in college or test the NBA waters, Brackins said, "I don't know right now."

Iowa State coach Greg McDermott said he's already discussed the matter with Brackins. McDermott said Brackins will go home to Palmdale, Calif., next week for spring break, then return to Iowa State before making any decision.

McDermott made the decision for the Cyclones to run almost exclusively zone defense for much of the game, and that strategy worked until midway through the second half. A 12-4 run by Oklahoma State broke a 50-50 tie and gave the Cowboys their biggest lead of the game at 62-54 with 8:54 left.

Muonelo, who has come off the bench the last seven games after starting for most of the season, had two 3-pointers and a 2-pointer during that stretch.

"He was really the wild card for them," McDermott said. "They had somebody step up and have really a great night."

The 6-foot-6 Moses displayed a variety of post moves while dueling Brackins on the inside and held the Iowa State star in check for much of the second half – with some key assists from Muonelo and James Anderson on double-teams – before fouling out with 2:39 left.

"At the beginning of the game, he caught the ball and I was right there ... and he hit it," Moses said of Brackins, who went 7 of 14 from the field. "I knew from there he was the real deal.

"We had to not let him go off, and I think we did a pretty decent job at that."

Brackins, who had 15 points and 10 rebounds before halftime, said Moses and the Cowboys "just did a really good job in the second half of trying to make it difficult for me."

Oklahoma State coach Travis Ford called the outings of Moses, who went 8 of 11 from the field, and Muonelo, who was 4 of 6 from 3-point range, the difference in the game.

"When you have got guys struggling from the 3-point line and Obi comes in and knocks down big shot after big shot, and then we got to a point where we said, 'Hey, you got to throw to Marshall. We have to penetrate the zone at some point.' ... He responded with obviously some great baskets and good percentages," Ford said.

Oklahoma State stretched the lead to as many as 16 points, making nine of 10 free throws in the final 3:20.

Anderson scored 14 points and Terrel Harris added 12 for Oklahoma State, which committed a season-low five turnovers. Byron Eaton had 11 points, seven rebounds and six assists.

The lack of turnovers was "huge," Ford said, "especially in a game that was a little slower than most. When you play against a team that played as much zone as they played, possessions are very important. We weren't shooting the ball very well. ... It was very important that we got as many shots as possible tonight. That's a huge stat when you are not making shots."

Jamie Vanderbeken went 4-of-5 from 3-point range and scored 12 points for Iowa State. Lucca Staiger hit 3-of-6 3-point attempts and had 11 points.

The Cyclones have lost 10 of their last 12 games against Oklahoma State.