Jonathan Gray started the night off well, but ran into trouble in the 4th when Matt Shortall hit an RBI double.
Then, Preston Beck hit a three-run jack to right in the 5th, making it 4-0 Mavericks.
"The fifth inning, I was extremely frustrated because there was no fight coming out of our dugout," said OU head coach Sunny Golloway. "We're new, we're young, we've got to develop an identity."
After a leadoff single for the Mavs in the sixth, Golloway pulled Gray and used three different relievers in the inning. UT-Arlington scored three runs making it a 7-0 game.
"Our bullpen didn't do its job," Golloway said. "We've got to find some guys that can help."
Offensively, the Sooners were not able to get anything going off Mavericks' starter Kasey Merck.
Merck went six scoreless innings, giving up five hits and striking out three. After Merck was pulled, OU tried to make things interesting.
Oklahoma never got closer.
"It's the second time we've lost in three years a midweek game at this ballpark," said Golloway. "I mean, think about that, that's truly remarkable, three years."
Shortall hit a three-run double in the eighth to push the Maverick lead to 10-2.
The Sooners pushed a run across in the ninth thanks to an error followed by a Hunter Lockwood single.
The game was originally scheduled for Tuesday, but the game time was changed due to weather. UT Arlington is now 2-0 vs. the Big 12 this season. Oklahoma travels to New Mexico to play the Lobos in a three game series beginning Friday at 7 p.m.