Michaela Pierandozzi led the No. 6-ranked Anteaters (19-5, 2-0 in conference) with two goals.
Jillian Yocum made seven saves for the winners.
The Gauchos fell to 16-12, 1-1.
UC Irvine 11,
Cal State Northridge 10
NORTHRIDGE — Annika Bergesen scored the game-winner with 41 seconds left to help the visiting Anteaters in the Big West Conference opener on Saturday.
Hannah Croghan and Danielle Warde had two goals apiece to pace No. 6-ranked UCI.
Jillian Yocum had six saves for the 'Eaters.
The No. 17-ranked Matadors fell to 14-15, 0-1.
ORANGE — Grace Konstanzer and Lindsay McCance had two goals apiece for the visiting Lions in the nonconference game Saturday.
MEN'S TRACK & FIELD
CLAREMONT — UC Irvine senior Charles Jock won the 400 meters on Sunday with a time of 46.78 seconds at Clarmont-Mudd-Scripps' Burns Track and Field Complex.
Jock also ran the third leg on the 4x400 relay that finished fourth (3 minutes, 13.27 seconds).
Stephen Brown tied for second in the pole vault with a mark of 15 feet, 7 inches.
Trevor Wightman was fourth in the 400 hurdles (52.59) and Riley Martin was fifth in the 1,500 in 3:53.98 for the Anteaters.
Nick Osborne was sixth in the 1,500 in 3:54.18.
UCI finished seventh as a team in the two-day meet.
On Saturday, senior Brennen Halliday was sixth in the 3,000 steeplechase (9:29.57).
WOMEN'S TRACK & FIELD
CLAREMOUNT — UC Irvine junior Ericka Nowell edged senior teammate Amber Middleton to win the 400-meter hurdles on Sunday at Claremont-Mudd-Scripps' Burns Track and Field Complex.
Nowell's time was 58.95 seconds, just better than Middleton's 58.96.
Middleton was second in the 100 hurdles (14.0 seconds) and UCI's 4x400 relay of KayC Wharton, Middleton, Kelly Collins and Nowell was second in 3 minutes, 43.13 seconds.
UCI's 4x100 relay of Kirma Helmer, Sanmisola George, Martina Michos and Breannca Fleming was second in 47.09.
UCI placed seventh in the team standings.