On a windy afternoon, the University of Hawaii baseball team blew an opportunity to win the opener of a Big West road series.

The Rainbow Warriors squandered five home runs, including a pair by third baseman Josh Rojas, in falling to Cal State Northridge 8-7 at Matador Field.

“I’m sick to my stomach the way we pitched today,” UH coach Mike Trapasso said in a telephone interview. “I feel I let our guys down. When we don’t pitch well, I feel it’s on me. I feel we weren’t good on the mound today and we handed them the game.”

Shortstop Dustin Demeter’s two-run homer and Rojas’ bases-empty shot gave the Rainbow Warriors a 3-1 lead in the third. Rojas and left fielder Adam Fogel hit back-to-back home runs to break a 3-all tie in the fifth.

But the Matadors answered against four UH pitchers. Brendan Hornung was chased after allowing four runs in five innings. Hornung, who entered with six walks in 76 2/3 innings, issued four on Friday. CSUN parlayed two of those walks into runs.

“I don’t second-guess taking him out for one second because he was done,” Trapasso said of Hornung’s pitch-command problems.

Trapasso said Jackson Rees usually is the first option for long relief. But Rees is scheduled to start today in place of left-hander Dominic DeMiero, who has experienced tenderness in his throwing arm.

Colin Ashworth opened the sixth — and departed six batters later after giving up Nolan Bumstead’s solo homer and Nick Sablock’s two-run smash for a 7-5 lead that CSUN would not relinquish.

“Colin wasn’t ready to get it done, and that’s on me,” said Trapasso, who doubles as the pitching coach. “Colin wasn’t the right choice. Every (pitch) was up, and he couldn’t throw anything for a strike.”

Matt Richardson also was inconsistent as Ashworth’s replacement, allowing a a run in 11⁄3 innings.

“Until I can teach them to be more consistent with more than one pitch for a strike,” Trapasso said of his middle-relief situation, “I’ve got to find somebody else, give somebody else a chance. Other guys are going to get opportunities. We’ve got other guys.”

Trapasso was particularly miffed that CSUN’s final run came from a player who reached by being hit by a pitch.

“In a situation where anything (hit) in the air is going to leave the park, you have to make sure you don’t give up freebies,” Trapasso said. “There were three or four runs scored on freebies — walks or hit batsmen. In these (windy) conditions, you have to make sure these are solo home runs. When you walk a guy and then give up a two-run home run, you’re just asking for trouble. We talked about that at length, but I obviously didn’t do a good job of getting that point across. Today was on me 100 percent. We have to do a better job. I have to do a better job.”

UH center fielder Dylan Vchulek went 2-for-5 to extend his on-base streak to 37 games in a row. But he was thrown out stealing and picked off first. In the seventh, Rojas was thrown out at the plate trying to score from second on a wild pitch.

“It was unwise, but it was aggressive,” Trapasso said. “You take your chances with Josh being aggressive. You don’t want to take that away from him. That’s Josh. That’s what makes him a good player.”