Texas' Dexter Pittman (34) takes a shot in the second half as Colorado's Jermyl Jackson-Wilson (31) defends at the Big 12 Conference men's tournament in Oklahoma City, Wednesday, March 11, 2009. Pittman scored 26 points in Texas' 67-56 win.

Oklahoma City, Okla. ? While sharpshooting star A.J. Abrams seems to be in constant motion running around the perimeter, Texas is developing a new game-changer who’s an immovable object inside.

Dexter Pittman dominated inside with a career-high 26 points and 10 rebounds, leading the Longhorns past Colorado 67-56 Wednesday in the first round of the Big 12 tournament.

At 6-foot-10 and about 300 pounds, the oversized Pittman had his way against Colorado’s interior defense. He started out 9-for-10 from the field with four dunks

“Not too many people can stop him,” said Abrams, a mere 161 pounds and just over half the size of a slimmed-down Pittman. “We’re going to keep giving him the ball and playing through him because he’s a dominant force inside.”

Texas’ Damion James had 11 points and 11 rebounds for his 15th double-double. Abrams, Texas’ leading scorer and the Big 12’s career leader in 3-pointers, added 10 points while matching his season-low with only six shots. It was only the sixth time this season Abrams didn’t take at least 10 shots in a game.

Instead, it was Pittman leading the way inside as Texas (21-10) avoided becoming the second straight fifth-seeded team to lose in the first round of the tournament. Colorado had an unprecedented upset of Baylor in the opening round last year, but never led this time around.

Texas will face fourth-seeded Kansas State in the quarterfinals Thursday. The Wildcats beat Texas in overtime in their only meeting this season, giving K-State the tiebreaker for the first-round bye in the conference tournament.

It was only the second time in Rick Barnes’ 11 years as coach that Texas didn’t have a first-round bye.

Pittman has developed into a viable option since shedding about 70 pounds in the offseason. He’s still working to improve his stamina and his concentration, which showed as he missed two point-blank layups in the final 4 minutes before finishing 9-for-13 from the field.

“This is all kind of new for him, in terms of playing the minutes he’s playing and knowing that we’re coming at him every time on the offensive end. I think that in itself is an adjustment, knowing that he’s got to produce,” Barnes said.

“People don’t realize that. It’s hard to be a legitimate 20-point scorer or 15-point scorer because every night people are game-planning for you. There’s no doubt that people have to game-plan for Dexter.”

That wasn’t the case a month earlier when Pittman had only four points in 12 minutes at Colorado, when Barnes found him ineffective in Texas’ defense and sat him down. Coaches reminded Pittman of that performance this week.

“I wanted to show Colorado that I could play,” Pittman said.

Colorado (9-22) didn’t have an answer inside and could never break through against the 2-3 zone deployed by the Longhorns, going 4-for-17 from 3-point range. Dwight Thorne II scored 15 to lead the 12th-seeded Buffaloes, who set a new school record with their 22nd loss of the season.

Coach Jeff Bzdelik said Colorado didn’t execute the game plan, which was to prevent Pittman from planting himself under the rim for dunks and easy baskets.

“He caught it so deep and we allowed him angles. We weren’t very forceful on him,” Bzdelik said.

Pittman bowled over Jermyl Jackson-Wilson for an open layup to start a run of eight straight Texas points midway through the first half that pushed the lead to 10. His third dunk of the game gave the Longhorns a 29-18 advantage, their largest of the first half.

The Buffaloes stayed in it from the foul line, going 11-for-12 on free throws, and closed to within 35-29 on Casey Crawford’s layup just before halftime. After Pittman opened the second half with another dunk, Thorne answered with 3-pointer to get Colorado within five.

Pittman then set up Justin Mason for a layup, and James tipped in a missed 3-pointer by Abrams to extend Texas’ lead. The Buffaloes were never again closer than seven, and the Longhorns’ lead swelled to 47-34 after Mason’s driving layup with 14:06 to play.

Pittman thwarted a brief comeback bid by the Buffs with a three-point play and a layup that restored the 13-point lead.

“The difference is he just keeps working, keeps going. I think the guys are starting to learn to get the ball to him,” Barnes said.

Levi Knutson finished with 11 points off the bench for Colorado. Cory Higgins, who scored a career-best 34 points when the Buffaloes took Texas to overtime in February, was limited to five points on 1-for-11 shooting.

Texas got a brief scare when top reserve Gary Johnson aggravated his injured left ankle while fighting for a loose ball with 5:11 left. Johnson had missed three games because of the injury before returning for the regular-season finale against Kansas on Sunday, but was able to walk off the injury and return to the game a few minutes later.