Senior Daniel Lenhart led the Bruins with a hat trick against the Gauchos.
The Bruins will face the winner of No. 8 Pacific/No. 9 UCSB on Friday at 3:00 p.m. at Long Beach St.
Gordon Marshall scored four goals in the 16-8 win over No. 4 Long Beach State.
Eight seniors played in their final home match, but sophomore Gordon Marshall led with four goals.
The Bruins will have eight seniors playing their final home game at Spieker Aquatics Center.