For a few minutes on Sunday, it looked like Stanford baseball might steal its first Pacific-10 Conference series of the year with two late comebacks on back-to-back days. Down by three in the bottom of the ninth, the Cardinal loaded the bases against Oregon State closer Eddie Kunz, bringing the potential winning run to the plate.

But Kunz — one day removed from hitting freshman Toby Gerhart in an almost identical situation en route to a 9-7, extra-innings win for Stanford — retired junior first baseman Randy Molina on a chopper, sealing the Beavers’ seventh win against the Cardinal in the last eight games, 8-6.

The Cardinal (18-23, 3-12 Pac-10) also dropped Friday’s series opener against the defending national champion Beavers, 13-7. Last year, Oregon State (34-9, 6-6) swept Stanford and ended its postseason run at the NCAA Super Regionals in Corvallis, Ore.

Stanford lost its fifth straight conference series despite scoring 22 runs against the Pac-10’s top pitching staff over the weekend. Junior second baseman Adam Sorgi led the Cardinal from the plate, going eight for 13 in the series, with five RBI.

“To be honest, for the first time all year I think it was a positive series,” Sorgi said. “We fell short. We wanted to take the series, especially from Oregon State... but we battled.”

Junior Erik Davis (2-1) took Sunday’s loss after giving up a two-run home run over the centerfield wall to Jason Ogata in the top of the first inning. The Ogata homer was one of three given up by Cardinal pitching.

Jorge Reyes (3-0) kept his perfect record intact allowing three runs over six innings in the series finale.

Sandwiched between the two losses, the Cardinal can take solace in the signature win of its season — Saturday’s dramatic, 9-7 win in extra innings.

Trailing 7-6 with a 2-2 count in the bottom of the 11th, junior Michael Taylor launched a walk-off, three-run homer off of reliever Greg Kelm to deep left field.

Taylor’s heroics came one at-bat after the preseason All-American grounded into a bases loaded, inning-ending double play in the bottom of the ninth, with the game tied, 6-6. But on his second opportunity, the only question off the bat was whether the ball would stay fair.

“We’ve had some emotional games... but we’ve been on the other end of it,” Taylor said. “Having something positive gives you a good feeling in your stomach when you go to sleep at night and makes you excited to come back to the ballpark.”

“They’ve kind of had my number over the last couple years, so I loved [getting the game-winner],” Taylor added. “I relished it.”

The game looked all but over for the Cardinal after OSU’s Jordan Lennerton led off the top of the 11th with his second solo home run of the game to straight-away centerfield off junior Nolan Gallagher.

Gallagher (3-5), a starter at the beginning of the season, pitched five innings in relief of freshman starter Jeff Inman. OSU’s Anton Maxwell (3-1) took the loss.

Head coach Mark Marquess was ejected in the 10th inning for arguing with the umpires after three consecutive Gallagher pitches appeared to be good enough for a strikeout.

“I ask the players not to argue,” Marquess said after the game. “If I see something that’s bad, I have to stand up for them. He missed two obvious strikes, and that’s not fair to our pitcher who’s out their working hard.”

After the ejection, Gallagher gave up a potential RBI single to right field, but Taylor came up with the ball quickly and fired a strike to sophomore substitute catcher Jason Castro, who tagged out Joey Wong at the plate.

“[That] was kind of the story of the day: Guys picking each other up,” Gallagher said. “If one guy screwed up, the next guy was picking you up.”

Stanford trailed 6-4 heading into the bottom of the ninth, but forced it to extra after Kunz — who entered the game with a 1.95 ERA and eight saves — went wild, walking two Cardinal batters and hitting Gerhart.

In the series opener, Stanford came back from an early four-run deficit to tie the game at 4-4 in the fourth, but starter Jeremy Bleich (1-8) surrendered a three-run, bases-clearing double to Lennerton in a five-run fifth.

Mitch Canham also cleared the bases with another three-RBI double in the ninth, putting the Beavers up by the final margin, 13-7. Pitcher Blake Keitzman (1-0) earned his first career victory in relief.

“There were a lot of walks, and we had a couple errors, but we gave up hits in big spots,” Marquess said. “And to their credit, they got the bases loaded and scored six runs with two swings of the bat.”

Stanford continues its homestand with its sixth game in eight days against Santa Clara tomorrow. The Cardinal has dropped both games to the Broncos this season, 13-5 and 6-3.

First pitch is scheduled for 6 p.m. at Sunken Diamond.