Oregon State jumped out to a 4-0 lead, with a run in the first, another in the second, and two in the third to chase Cougar starter David Stilley.
Beavers' starter Jorge Reyes retired the first nine men he faced, but ran into trouble in the fourth. The Cougs scored three in that inning. The Beavs added a run in the fourth but the Cougars plated three more in the sixth to take a 6-5 lead.
Ortiz' dinger in the seventh tied it up before WSU produced a run scoring single in the top of the ninth to give the visitors the win. Oregon State outscored the Cougs in a three game series by a total of 20-16 but still lost two of three.
The Beavers have five games left in the regular season and they could figure in as critical to OSU's postseason dreams. After being ranked much of the season, the Beavs were clinging to No. 25 in the USA Today/ESPN coaches poll and now with a series loss to WSU, now sit at No. 5 in the Pac-10 with a 13-11 mark.
On the plus side for Oregon State, their overall record stands at an impressive 31-16.
Oregon State returns to the diamond on Tuesday, May 19 against Oregon for a two-game series at Goss Stadium. First pitch is scheduled for 5 p.m. The Beavs conclude the season with a three game road series at Stanford May 22-24.
Before the game, Oregon State honored seniors John Wallace, Koa Kahalehoe, Kyle Foster, Mark Grbavac, and Logan Boyd, who were playing their final weekend game at Goss Stadium.
With 2,959 in attendance on Sunday, the Beavers posted their 11th crowd of 2,500 or more this season.
Beavers drop series finale, eye final five
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