Arizona had 15 hits and scored eight runs in the eighth. Its 15 runs were the most Oregon State has allowed all season.
Alfonso Rivas led Arizona with three hits, and Cameron Cannon led with four RBIs, which all came via an eighth-inning grand slam.
Oregon State ace Luke Heimlich entered 7-0 with a 2.42 ERA, but was crushed by the Arizona offense early and often.
Heimlich only pitched 3 1/3 innings, allowing six earned on nine hits with two walks and a couple of hit batters.
Arizona pitcher Michael Flynn got his fifth win of the season. He allowed four earned runs over 5 2/3 innings while walking three and striking out five.
Arizona had traffic on the base paths in seemingly every inning.
Oregon State scored on a squeeze bunt in the first, but the Wildcats countered with four hits through their first five batters, and Rivas tied the game with an RBI single to right, which was followed up with an RBI single by freshman Blake Paugh.
Oregon State tied the game in the second on an RBI double by Cayden Grenier, but Arizona answered with two more runs thanks to a Rivas double down the right field line.
The fourth and seventh innings saw the Wildcats add two and one more run respectively before the eighth-inning outburst.
During that outburst, Arizona had three singles, a double, a safety squeeze bunt, a bases loaded walk, a bases loaded hit by pitch, and finally, a grand slam by Cannon to cap off the scoring.
Nick Quintana was 2-for-4 with two RBIs and two runs scored. Ryan Haug was 2-for-3 with three runs scored and an RBI and Seve Romo, who made his first start at shortstop, was 2-for-5 with an RBI and a run scored.
Before Arizona’s eight-run eighth Oregon State made things interesting. With the score at 7-4, Tylor Megill walked Grenier with runners on the corners, but the fourth ball skipped past UA catcher Cesar Salazar to the backstop.
Alertly, Salazar retrieved the wild pitch and made a quick throw to Megill covering home where he tagged an overzealous Beaver for the final out of the inning.
The Wildcats are now 18-11 and 3-5 in the Pac-12. They will go for the series win Sunday at 12:05 p.m. PT at Hi Corbett Field.