Colorado guard Alec Burks (10) is pressured by Iowa State forward Jamie Vanderbeken (23) as he goes up for a shot during the first half of an NCAA college basketball game in the first round of the Big 12 coference tournament Wednesday, March 9, 2011 in Kansas City, Mo.

Kansas City, Mo. ? Alec Burks scored 25 of his 29 points in the second half and Colorado unleashed a 12-2 run in the final minutes to slip past 12th-seeded Iowa State 77-75 Wednesday in a hard-fought first-round game in the Big 12 tournament.

Jake Anderson had a career-high 33 points for the Cyclones (16-16), the second-highest total ever scored by a college player in the Sprint Center. The Iowa State senior was 13 for 20 from the floor, including 3 of 5 from 3-point range, but the Cyclones lost their sixth straight Big 12 tournament game.

Burks, one of two unanimous picks on the All-Big 12 team, also had 15 rebounds and six assists. He was 9 for 16 from the floor and 11 of 14 from the foul line as the Buffaloes (20-12) advanced to the second round against No. 19 Kansas State, a team they beat twice in the regular season.

The Cyclones were leading 66-64 when Diante Garrett’s 3-pointer from the baseline and a foul shot by Jamie Vanderbeken gave them their biggest lead, 70-64, with 3:02 to play.

But Burks came right back with a bucket and Levi Knutson, after an Iowa State miss, swished a 3-pointer that made it 72-69 as the Buffaloes went on their game-clinching run.

Cory Higgins had 16 points and Knutson had 12 for Colorado, which is gunning for its first postseason invitation in five years. Garrett, extending his school record of 128 games played, had 19 points and six assists for Iowa State.

Burks, making one acrobatic, off-balance shot after another, tied it 72-all with a three-point play and then gave Colorado a 74-72 lead with an awkward 10-footer from the lane.

Andre Roberson rebounded an Iowa State miss, drew a foul and sank a pair of free throws for a 76-72 lead.

With 8 seconds to go, Anderson made a free throw that was matched by one from Higgins. Anderson’s bucket closed out the scoring.

Burks, a native of the Kansas City area who was virtually ignored coming out of high school by Missouri, Kansas and Kansas State, was 7 for 10 in the second half.