After dropping its first Pacific 10 Conference series to ASU, the No. 18 Arizona baseball team was raring to get back on the field against a conference opponent.

Unfortunately for the Wildcats, this weekend’s series against No. 23 Oregon State (20-7, 2-1 Pac-10) was nearly a mirror image of the series in Tempe, with Arizona winning the first game only to drop the next two.

“”Their guys pitched well, we did not,”” head coach Andy Lopez said. “”It was a tough weekend.””

Arizona’s rotation struggled after Kurt Heyer opened the series by throwing the first complete-game shutout of his career as the Wildcats dismantled OSU 18-0 in a game that featured five Beaver errors.

The Wildcats (20-9, 2-4) scored 12 runs in the sixth inning while Oregon State cycled through five different pitchers — including highly touted starter Sam Gaviglio, who allowed 10 runs in the outing, but only four were earned.

Though Arizona’s huge inning kept Heyer off the mound for over half an hour, the right-hander didn’t feel any ill effects from the wait.

“”I felt awesome,”” Heyer said. “”I played catch a little bit just to keep my arm fresh. Whether you’re up 12 runs or one run, you just have to keep the same mentality and pitch like it’s 0-0.””

Saturday’s game was a different story on the mound.

Kyle Simon, who didn’t attend Thursday’s practice or Friday’s game while battling a stomach bug, obviously wasn’t himself on Saturday — allowing five runs in 5.2 innings while walking multiple batters in an outing for the first time this season.

“”The ball just didn’t behave today,”” Simon said. “”You should never feel super good going into an outing, but you should never feel this bad either. But I fought through it and did what I could to get the team into a winning position, but we just couldn’t get it done today.””

Arizona pitchers allowed two three-run home runs — one to Ryan Dunn and another to Ryan Barnes — the first career home runs for both hitters, and Dunn’s first career extra-base hit.

Before Dunn’s blast, a questionable call on a play at first extended the inning. With two outs, shortstop Alex Mejia fielded a ball in the hole, and his throw to first appeared to beat the Oregon State runner, but umpire Scott Higgins called him safe.

“”That’s probably one of the worst umpire calls I’ve seen,”” Simon said. “”That changed the game in all reality, but with pitching you should have the ability to forget about the last pitch, so that was bad on my part for not getting the next guy out.””

Arizona’s offense pushed across three runs in the first inning on Saturday, but was able to manage only one more run in the 10-4 loss. The Wildcats trailed only 6-4 after Dunn’s homer in the sixth, but a 4-run Oregon State ninth put the game out of reach.

Arizona stumbled out of the gate in Sunday’s series finale, with starting pitcher Tyler Hale allowing seven runs — all earned — in 2.2 innings of work in the 8-4 loss.

“”(Hale) was horrible,”” Lopez said. “”He couldn’t throw strikes, couldn’t locate, he was up in the zone. He was not very good.””

The Wildcats took control of some momentum with a 2-run home run off the bat of Robert Refsnyder in the sixth inning, but weren’t able to do any further damage.

“”Baseball’s a funny game,”” Refsnyder said. “”Friday we put up big numbers, but Saturday and Sunday we struggled.””

Though Arizona is now in the bottom half of the Pac-10 standings, Refsnyder said that there isn’t any sense of panic.

“”No panic,”” Refsnyder said. “”We’ll figure it out. We’ll be good from here.””