The Anteaters did not, however, break from form, as they improved to 11-0 at home this season, which is a school record to open the season.
Junior center fielder Christian Ramirez , a community college transfer who came into the game six for 35 in his Division I career, was four for four with a walk, a triple and a double to pace a 15-hit attack for the winners (16-6, 1-0 in conference).
UCI, ranked No, 19 in the USA Today/ESPN poll, had been struggling offensively, managing just 24 hits and five runs in its previous four games, including a 4-0 nonconference win Tuesday at USC.
Five Anteaters had at least two hits. Senior right fielder Sean Madigan went three for five with two runs batted in and junior catcher Ronnie Shaeffer was two for four with two RBIs.
Junior first baseman Jordan Fox was two for three and senior third baseman Brian Hernandez was two for five for UCI.
Hernandez also pitched a scoreless ninth inning to record his fifth save, securing the win credited to starter Matt Summers. Summers allowed three earned runs on five hits in 6 1/3 innings. He walked five and struck out two.
A six-run fifth inning erased a 2-0 deficit for the 'Eaters, who had six hits in the frame, all in the span of seven hitters.
Fox and Hernandez singled to open the inning. After a flyout, junior designated hitter Jordan Leyland drove in a run with a single, as did Madigan. Shaeffer then yanked a two-run double inside the third-base bag and Ramirez's fly ball bounced under a diving attempt by the right fielder, allowing him to race all the way to third.
UCI led, 7-3, into the eighth, but a three-run home run by Drew Muren drew the Matadors (14-12, 0-1) within one run.
UCI, which left 12 runners on base, cashed in a pair of Northridge errors, two walks and a Madigan RBI single for two insurance runs in the eighth.
Hernandez, who had gone nearly three weeks without a save, issued two one-out walks and a single to load the bases. But he struck out Adam Barry looking and induced a weak comebacker for the final out, allowing UCI to win their second straight, following a four-game losing streak.
Hernandez, who had not pitched since high school, has now failed to allow an earned run in 12 innings.
"It was a very important win," UCI Coach Mike Gillespie said. "I think Northridge is probably pretty under-appreciated and under-respected. [The Matadors, under first-year coach Matt Curtis] are pretty competitive."
Ramirez said he never lost his competitive edge, despite coming in with a batting average of .171.
"What happened in the past, I just tried to leave it in the past and keep working hard," said Ramirez, who was beaming after the victory.
"You can never lose your comfort and confidence, because once that goes, you might as well not even step on the field."
Ramirez, who was a home run short of the cycle, steps on the field today hitting .326, which is topped only by Fox (.375) among UCI regulars.
"It feels good to get those knocks and do whatever it takes to help the team win," Ramirez said.
Big West Conference
UC Irvine 9, Cal State Northridge 6
SCORE BY INNINGS
CSUN 000 021 030 – 6 7 2
UCI 000 060 12x – 9 15 2
Gorski , Fredrickson (5), Juarez (5) and Keller; Summers, Litchfield (7), Hernandez (9) and Shaeffer. W – Summers, 3-2. L – Juarez, 2-4. Sv – Hernandez (5). 2B – Ramirez (UCI), Shaeffer (UCI), Barry (CSUN), Bowen (CSUN). 3B – Ramirez (UCI). HR – Muren (CSUN).