Junior third baseman Taylor Sparks' two-out single in the bottom of the eighth drove in the winning run for the host Anteaters, who extended their Big West Conference winning streak to 11 on Saturday.
UCI (31-14, 13-1 in conference), ranked No. 20 by Collegiate Baseball, has now won six straight games. The Anteaters, who began the day 1.5 games ahead of second-place Cal Poly San Luis Obispo, clinched the series victory against the Gauchos (26-13).
Junior closer Sam Moore earned his NCAA-leading 21st save to become the Big West single-season record holder by working a scoreless ninth. He now has five saves in the last six games and is closing in on the NCAA single-season record of 24.
Junior Evan Manarino earned the win in relief of starter Elliot Surrey, who allowed seven hits and two runs in 7 1.3 innings.
Connor Spencer and Jonathan Munoz were both two for four to key UCI's eight-hit attack, while Adam Alcantara added an RBI for the winners.
UCI tied the game in the seventh inning on Alcantara's RBI groundout and a throwing error that plated one unearned run.
The two teams conclude the series Sunday at 1 p.m.
Golden State Athletic Conference Tournament
EL CAJON — Vanguard University dropped a pair of games on Friday and was eliminated from the four-team, double-elimination event at Grossmont Community College.
The No. 22-ranked Lions lost a winner's bracket semifinal, 22-9, to top-seeded and No. 7-ranked San Diego Christian, then fell, 17-7, to No. 24-ranked Westmont.
The Lions (32-21) will hope to receive an at-large bid into the NAIA Tournament field.
Taylor McKnight was four for five with two runs batted in and Bret Collins was three for five against Westmont, which built a 13-0 lead.
McKnight, who was six for nine with five RBIs in the two games, homered against San Diego Christian, which rallied from a 6-0 deficit.
Collins (four for nine), Brandon Sandoval (three for eight) and Thomas Mobley (three for 10 with three RBIs) also had productive days for Vanguard, for which seven of eight pitchers used allowed runs in the two games.
WOMEN'S TRACK & FIELD
Steve Scott Invitational