UCSD (37-20) advances to the West subregional final for the second consecutive season and will face No. 3-seed Dixie State at 12:00 p.m. on Sunday. The Tritons will need to beat the Red Storm twice in order to advance to the Super Regional next weekend.
CSUMB, the highest-seed and host of the West Region II Tournament, finishes the season at 46-14 overall.
Kirsten Willmon ignited the scoring in the second inning for the Tritons, lacing a one-out single to left field to drive in Emily McQuaid. Willmon took third on an overthrow, but was picked off on a failed squeeze play on the first pitch to Brown.
Brown pounded Kylie Linnane's (13-4) next offering over the scoreboard in left to put the Tritons up 2-0.
Meanwhile, Gaito (25-9) kept the Otters bats at bay, surrendering just a single hit over the first four innings. The senior right-hander struck out two, walked none and forced the Otters into 15 groundball outs in the contest.
Lesovsky made it 4-0 in the fifth, bringing Monique Portugal home with a line-drive off the left field foul pole. Willmon followed with a single, forcing Linnane out of the circle for reliever Cory Reinhardt.
Brown, the first batter Reinhardt faced, tacked on another with a two-out home run to left-center.
The first three batters in the Triton line-up - Lesovsky, Willmon and Brown - were a combined 5-for-7 with five RBI, three runs and three home runs. McQuaid was 1-for-1 with a run and tallied a game-high seven assists at third base. Willmon went 2-for-2.
UCSD and CSUMB met seven times this year. The Otters won the first five contests between the teams, but the Tritons took down CSUMB when it mattered most - in the CCAA Championship game on April 29, and then today in the West Region semifinal.
DSC defeated UCSD, 3-2, in the opening game of the West Regional before beating CSUMB on Saturday morning to advance to Sunday's final.