"We had it to a one-possession game and had, I think, four different attempts at it," said head coach Sherri Coale. "We were down one but we just weren't able to get over the hump."
It was 59-58 with 5:02 to play after center Nicole Griffin banged home a layup.
But guard Aaryn Ellenberg misfired on a 3-pointer, center Joanna McFarland committed a turnover and came up short on a 10-footer moments later, as OU couldn't capitalize on a 3:15 drought by the Buckeyes.
The Buckeyes eventually broke that dry spell and connected on a pair of baskets moments later that left them up 65-58 with under a minute to go.
OU closed to within four but it was too little, too late.
"We had to dig, and that's tough," Coale said. "It is tough even for a veteran team to have to climb from behind the whole time. It is a double whammy for a really young team, but again, I think that's why we grow up from this. That is why we are in these situations and we will figure out it is a lot easier to play from ahead."
The Sooners trailed by as much as 13 in the first half after spotting Ohio State a 7-0 lead to start the game.
One bright spot, though, was the emergence of Griffin, who scored 10 points and brought down seven rebounds to go along with three assists, two blocks and a steal.
And it could have been more, the way she imposed her will.
"The other games in the beginning of the season I didn't play that well," Griffin said. "I wasn't aggressive enough and I feel like I got a lot better this game. We've been doing that stuff in practice that's been helping me with that. I feel like it's a good start and that, this year, I'm one of the people that we need to look for and I just have to produce in the paint."
Guard Amber Stokes and center Ashley Adams each managed 12.
The Sooners will now head to Fresno State for a road contest at 9 p.m. CT Thursday, while the Buckeyes return home to face Canisius.