OSU, which had a seven-game win streak snapped, twice had a tying runner on first base in the bottom of the ninth, but it failed to score against Cal-Davis closer Max Cordy.
The Cowboys (9-2) host Missouri State at 4 p.m. Tuesday.
SOONERS BEAT COUGARS
Top-ranked Oklahoma returned to its winning ways Sunday, beating Houston 4-1 in softball at Marita Hynes Field in Norman.
Brittany Williams and Georgia Casey each had two RBIs for the Sooners (18-1).
OU next plays 3 p.m. Wednesday at Wichita State.
COWGIRLS DROP TWO
Former Big 12 rival Nebraska took care of business in a doubleheader vs. Oklahoma State, sweeping the Cowgirls 3-0 and 10-5 in Stillwater.
Tarah Ettinger was one of the few bright spots for OSU (7-11), collecting three hits and three RBIs over the two games. She had a three-run homer in first inning of the nightcap. That helped tie the score 5-5, but the Cornhuskers took the lead for good in the top of the second inning.
OSU next plays Friday, when it hosts Santa Clara (Calif.), Northern Iowa and Cleveland State in the Mizuno Classic.