Pop Isaacs had 18 points, including 13 in the second half when the Red Raiders (16-3, 5-1) overcame a nine-point deficit.
McMillian made 10 of 13 shots and was 6 of 8 from 3-point range for the Red Raiders, who shot 52.6% from the field.
“What a tremendous environment, what a great college basketball game,” Texas Tech head coach Grant McCasland said. “I thought their physicality as the game went on really caused us problems. We just stayed in the fight and you know, ultimately, I did think our ability to get some stops and get out in transition opened the game up.”
Isaacs made a pair of free throws with 2.1 second left in the game to give Texas Tech an 85-81 lead. Oklahoma’s Rivaldo Soares made a 3-pointer as time expired. He led the Sooners (15-5, 3-4) with 19 points and 10 rebounds.
Oklahoma has lost four of its last six games and six of its last eight against Texas Tech.
Otega Oweh had 14 points and Milos Uzan and Sam Godwin each scored 13 for the Sooners, who shot 47.5% for the game and 42.3% from 3-point range. Uzan missed a shot with four seconds left that would have tied the game.
The Sooners struggled at the free-throw line, converting 15 of 24 shots compared to 16 of 19 for the Red Raiders.
“I thought we did some really good things offensively, time and time again against an elite defensive team,” Oklahoma coach Porter Moser said. “Our second half defense got us, and we left nine free throws on the table.
“These guys care, and this is not a broken locker room. This is a locker room that is hurting right now. We didn’t get it done, but it isn’t because we have a fractured locker room.”
Texas Tech: The Red Raiders proved Saturday they could win with limited production from their leading scorer, Isaacs, who came in averaging 19.8 points per game in conference play. Isaacs was limited to five points in the first half, but the team got double-figure scoring from three others, including Joe Toussaint, who had 14 points, including four clutch free throws down the stretch.
Oklahoma: The Sooners’ streak of seven consecutive weeks in the top 15 is in jeopardy. They have dropped two straight and continue to struggle against ranked teams. The Sooners’ only top 25 win this season came in November against then-No. 23 USC.
Texas Tech: Visits TCU on Tuesday night.
Oklahoma: Visits Kansas State on Tuesday night.
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AP college basketball: https://apnews.com/hub/ap-top-25-college-basketball-poll and https://apnews.com/hub/college-basketball