Eugene, OR -- Brandon Eisert's one-run outing wasn't enough for Oregon State as the Beavers fall to Oklahoma State, 1-0.
Eisert went eight innings allowing just one run while striking out eight. The Cowboys' only run came in the seventh inning on an Alex Garcia single.
The Beavers were held to just two hits on the night recorded by Tyler Malone and Zack Zalesky.
Oklahoma State's Jensen Elliot pitched seven scoreless innings of work followed by two shutout innings from Peyton Battenfield.
The Beavers drop to 31-12 overall.
Game two of the three game series is set for 6 p.m. on Saturday at Goss Stadium.
As for Oregon, the Ducks allowed 12 runs in the final three innings and fall to Arizona, 17-6.
The Ducks took 5-0 lead in the third inning after a two-run home run by Jonny DeLuca. The Wildcat bats woke up, tying the game in the bottom half of the inning.
Arizona tallied six runs in each the seventh and eighth innings to secure the victory.
The Wildcats recorded 16 hits for the game.
Keaton Chase suffered the loss for the Ducks after allowing three earned runs in one inning of work. Chase was one of seven different Oregon pitchers to enter the game.
Oregon also had trouble defensively committing six errors.
The Ducks drop to 23-20 overall and 8-11 in Pac-12 play.
Game two of the series is set for 6 p.m. on Saturday at Hi Corbett Field in Tuscon, Ariz.