Oklahoma City, OK -- (Sports Network) - Dexter Pittman scored a career-high 26 points and grabbed 10 rebounds in leading Texas to a 67-56 win over Colorado in the opening round of the Big 12 Conference Tournament.

The fifth-seeded Longhorns (21-10) move on to the quarterfinals for a clash with fourth-seeded Kansas State on Thursday.

Damion James posted 11 points and brought down as many boards while A.J. Abrams netted 10 with five steals for Texas, which had its late-season upset of second-ranked Oklahoma overshadowed somewhat by a pedestrian finish to the regular season with six losses in the final 11 outings.

Dwight Thorne totaled 15 points and five rebounds while Levi Knutson notched 11 and six for the 12th-seeded Buffaloes (9-22), who suffered 11 single-digit losses this season by an average of 4.5 ppg, but nevertheless won just once in 16 league games and closed out the regular season with 11 consecutive setbacks.

Jermyl Jackson-Wilson added eight points and six boards in defeat.

Two free throws by Knutson had Colorado within two close to nine minutes in, and a three-ball moments later from Thorne was good for only a 25-18 deficit.

The Buffs got to the line 12 times in the first half and missed only one, helping to offset connecting on just eight field goals as they trailed by six, 35-29, entering the break.

Texas took control in the second half and opened up a 47-34 advantage nearly six minutes in behind a 12-5 run to start the final 20 minutes. Five straight points from Pittman a short time later had the Longhorns holding firm to their 13-point lead.

They would retain a double-digit lead until Knutson sank two from the line and Nate Tomlinson followed with a layup with 6 1/2 minutes left, bringing the Buffs within seven, 59-52. But Texas scored six of the next eight points to put the game out of reach.