The Sooners seized a 1-0 lead in the top of the first inning when center fielder Max White recorded his team-leading 35th RBI of the season, plating left fielder Erik Ross, who led off the game with a single up the middle and moved over to second on a sacrifice bunt.
But it was all OSU from there, as it scored six unanswered runs to finish the game.
Cowboy right fielder Trey Whaley scored on a sacrifice fly to tie it at one in the bottom of the third.
The Cowboys added three more in the sixth on four hits and a passed ball, taking a commanding 4-1 lead.
They finally chased Sooner starter Damien Magnifico in the seventh after allowing four earned runs in 6 2/3 innings, striking out five and walking four in getting tagged with his first loss of the season.
Meanwhile, OSU starter Kyle Ottoson dealt, picking apart Sooner batter after Sooner batter.
He retired 12 straight at one point en route to lasting 8 1/3 innings, striking out four and walking just one in grabbing the victory."We won eight straight until today and we faced a guy that pitched a really good game," said OU head coach Sunny Golloway.
White led the Sooner offense with his fourth straight multi-hit game, going 2-for-4 with an RBI.
OU, however, was outhit 10-5 by OSU.
The only plus for the Sooners, who dropped to 26-15 overall, is this one doesn't go down in the Big 12 books.
"It's an in-state game, it's a rival game," Golloway said. "It's not a conference game and that's where we're fortunate. We still get the opportunity in the Big 12 series against them and that will be in important to us. Our Big 12 record is going to be important to us."
Currently, the Sooners sit one game behind the Cowboys in the Big 12 standings, owning a 7-8 record to their counterpart's 8-7 mark.
The two are slated to meet May 4-6, including once in Tulsa and twice in Oklahoma City, so the Sooners could sweep the conference series and win the season series 3-1 should they win all three.
Before then, OU has five more contests, including tomorrow's 6:30 p.m. matchup against Dallas Baptist and the upcoming weekend set against Kansas on the road.
"To have to sit and wait and go to Lawrence would be really tough," Golloway said. "Tomorrow we are going to play a team that has an RPI of 30 something and we need to go out and find victory. That can at least balance out the damage that we did today."?
The Patriots scored four in the ninth to rally and win the first meeting 7-6 between the teams back on March 13 in Dallas, so OU will have a chance to avenge that.