They have now lost four in a row and six out of seven and are trending the wrong way at the wrong time.
"Yeah, there's no doubt about that," said a somber Sooner head coach Sunny Golloway after Saturday's defeat. "But again, you know, it's circumstance more than anything. And it is what it is, and we've gotta be tough. We've gotta persevere."
His club most certainly wasn't able to do so on this day thanks to a number of missed opportunities and mishaps.
In the bottom of the seventh with OU trailing 3-2 and runners at first and second with nobody out, left fielder Hunter Haley couldn't get a bunt down and move them over.
Instead, Haley struck out and another strikeout and flyout later, the Sooners left the pair stranded.
Still down one an inning later, a leadoff double for the Cowboys and error by OU center fielder Craig Aikin allowed a runner at third with nobody out.
When it seemed like the Sooners wouldn't escape unscathed, though, OSU's Gage Green swiped home on an 0-2 count off closer Jacob Evans to make it 4-2.
The Sooners got one back in the bottom of the eighth on third baseman Garrett Carey's sacrifice fly, but that was all, as they left another stranded in scoring position.
"It wasn't what OSU does, it was what we were doing," said OU first baseman Matt Oberste. "We had a lot of popups. We couldn't get the ball on the ground to force them to make errors."
On top of that, OU couldn't really catch any breaks.
Right fielder Max White hit what seemingly was a game-tying three-run blast in the bottom of the sixth, but it twisted just foul outside the left field foul poll.
"You know, from where I was, I was arguing that it was fair clearly because I thought it had a chance over the top," Golloway said. "I'm not on the line. So, of course, you know, the home team guy that's hitting's head coach is gonna think that's a fair ball. I thought it was a fair ball."
The Cowboys took an early 2-0 lead in the top of the second when catcher Victor Romero and third baseman Robbie Rea recorded RBI doubles and triples, respectively.
They made it 3-0 in the fifth on shortstop Randy McCurry's RBI single up the middle.
OU struck back to within one on second baseman Hector Lorenzana's two-run single back through the box in the sixth.
The Sooners will now try to salvage the series when the two conclude the three-game set at 1 p.m. CT Sunday.