Oklahoma State rallied for a series-opening 6-5 win over No. 24 San Diego Friday at Allie P. Reynolds Stadium, but the 12th-ranked Cowboys came up short in the nightcap of the doubleheader, dropping a 10-6 decision.
With the doubleheader split, OSU is now 11-3 on the season, while the Toreros will enter Sunday's series finale with a 9-4 mark.
In both games, the Cowboys fell behind big early.
The opener saw the visitors tag OSU starter Tyler Nurdin for five runs on four hits in their first at bat, getting a two-RBI double from Jesse Jenner and a three-run home run off the bat of Josh Goossen-Brown to take a 5-0 lead.
But the Cowboy bullpen came on and got the job done over the final eight frames, and OSU's offense battled back to notch the win. The triumph marked the Cowboys sixth come-from-behind victory of the season.
Trailing by five, OSU rallied for four runs in the bottom of the fourth off USD starter P.J. Conlon, who retired the first nine Cowboys in a row before walking Tim Arakawa to open the fourth.
Following the walk, Donnie Walton doubled to bring home OSU's first run, and two batters later, an RBI single by Dustin Williams made it 5-2. Up next, Conor Costello blasted a two-run homer, his second of the season, to pull the Cowboys within one.
USD clung to its lead until the eighth. In that inning, Arakawa once again got things going when he was hit by a pitch to lead off. He eventually came around to score on an RBI by Tanner Krietemeier.
With the bases loaded and one out in a 5-5 game, Zach Fish delivered what proved to be the game-winning RBI on an infield single before the Toreros got out of the inning without further damage.
OSU's late rally allowed Brendan McCurry to earn his first win of the season as the Cowboys' closer worked the final 1 1/3 innings without allowing a run to move to 1-0.
McCurry was the last of four relievers who came up big for the Cowboys as the group allowed just three hits and kept USD off the scoreboard over the final eight innings. Blake Battenfield relieved Nurdin and worked four innings, while Vince Wheeland gave OSU 2 2/3 frames.
In the nightcap, the Cowboys got behind and were never able to dig out of the hole as, once again, USD was able to jump on OSU's starter early.
This time it was freshman right-hander Thomas Hatch who surrendered four runs on four hits in the top of the first inning as the Toreros took command.
In the fourth inning, the Cowboys would rally for three runs on just one hit, scoring on a wild pitch, a throwing error and a sacrifice bunt RBI by Aaron Cornell.
But this time, USD would answer, getting a pair of runs in its next at bat to go up 6-3 after 4 1Ž2 innings.
OSU would make things interesting late, however.
Still trailing by three, the Cowboys opened the eighth with Costello's second homer of the day. Gage Green followed that with a double before pinch hitter Saulyer Saxon flied out. After Garrett Williams walked and pinch runner Corey Hassel stole second, OSU had runners on second and third with just one out.
Up next, Fish fouled out before Arakawa came up with a clutch two-out hit, an RBI single to left field to make it 6-5. But Donnie Walton lined out to end the inning with a pair of Cowboys stranded on the bases.
The Toreros finally solved OSU's bullpen in the ninth, batting around and scoring four runs on four hits against three different Cowboy pitchers to put them up 10-5 and help seal the win.
The two teams will play the series-deciding contest Sunday beginning at noon.