A promising start to the Big West baseball season quickly turned into a nightmare for the Hawaii baseball team.

Losers of nine of their past 10 entering this weekend’s series against Cal State Fullerton, the Rainbow Warriors suffered their most brutal defeat yet, allowing an unearned run in the bottom of the 10th inning to lose 1-0 to the Titans on Friday night at Goodwin Field in Fullerton, Calif.

Tanner Pinkston singled home Jared Deacon with two outs in the bottom of the 10th after shortstop Austin Wobrock misplayed a potential inning-ending double-play ball.

Cal State Fullerton (19-17, 4-6 Big West) had scored only one run in its past 43 innings before Pinkston’s hit off UH reliever Juliene Jones (0-1).

Sophomore Thomas Eshelman (6-1) pitched all 10 innings for the Titans, allowing six hits and no walks with six strikeouts.

"It’s very disappointing because you had your chance against a great pitcher like Eshelman and if you score one run, that’s all it was going to take," Hawaii coach Mike Trapasso said. "We had a chance to get that one run first and didn’t get it done."

Hawaii (15-23, 3-10) has lost 11 of 14 one-run games this season, including the past six.

The Rainbow Warriors wasted a gem by starter Matt Cooper, who struck out a career-high 11.

Cooper allowed only four hits and two walks and matched Eshelman for nine innings.

All five Titans who batted with runners in scoring position against Cooper struck out.

Cal State Fullerton had its first two batters of the game reach base and sacrificed to second and third. Cooper went to work mixing all four of his pitches, including a nasty curveball that helped strike out JD Davis and Keegan Dale to end the inning.

Cooper retired 10 in a row until a one-out single by Davis in the fourth but struck out Austin Diemer with Davis on second.

Dale connected on a two-out double in the bottom of the ninth before Cooper blew a fastball by Taylor Bryant for his 11th strikeout on his 132nd pitch.

"It was an unbelievable college baseball game, but it’s just a crying shame that you waste a pitching performance like that," Trapasso said. "That was one for the ages. It was one of the best pitching performances we’ve seen from a Hawaii pitcher."

Adam Hurley had two of Hawaii’s six hits, but the Rainbow Warriors were 0-for-5 with runners in scoring position.

Stephen Ventimilia and Kaeo Aliviado hit consecutive one-out singles in the ninth inning to put the go-ahead run on third base with one out.

Jordan Richartz, who had a five-game hitting streak come to an end, showed bunt on the first pitch from Eshelman but eventually got ahead 3-0 in the count before striking out.

Eshelman then got Marc Flores to fly out to right to strand Ventimilia on third.

"When you’re facing a guy like Eshelman, who is going to be one of the top-10 picks in next year’s draft, you might only get one chance (to score) and we had that chance," Trapasso said. "We’ve got to get that runner in and it’s just a shame, that’s the only thing you can take away from a game like that."

Matt Miller and Wobrock had UH’s other two hits.

Aliviado extended his consecutive games streak of reaching base to 22, while Cooper lowered his season ERA to 1.72.

Pinkston finished with two of Fullerton’s six hits.

Game 2 of the series is Saturday at 2 p.m. and will be broadcast on ESPNU.