Winger Nick Schlobohm had a hat trick and flyback Garrett Brewer scored two tries in No. 4 Saint Mary's 55-31 rugby victory over top-ranked Cal at Pat Vincent Field on Saturday.
The Bears (16-2), playing their regular season finale, had the run of play for much of the day, but the Gaels (14-1) countered effectively.
"Against a great Cal program we just want to play respectable rugby," Gaels coach Tim O'Brien. "We did that today."
Cal captain Seamus Kelly scored in the first half, and the Bears got second-half tries from Andrew Battaglia, Harry Adolphus and Nicklas Boyer.
"We gave up a half-dozen lightning-strike-quick tries that mostly came from transition moments, most from 50 meters out," Cal coach Jack Clark said.
Vince Bruno went 3-for-3 with a home run, but Cal (14-13, 3-5 Pac-12) fell 3-1 at Washington State.
Austin Davidson hit a grand slam, powering Pepperdine to a 10-4 victory over Saint Mary's (13-16, 5-3 WCC). Collin Ferguson hit a two-run homer for the Gaels.
Birthday boys Casey Munoz and Jose Vizcaino Jr. both had two hits to help Santa Clara (12-18, 3-5 WCC) to a 7-3 victory over Portland.
Saint Mary's (14-17) opened WCC play with a doubleheader sweep of Loyola Marymount at Cottrell Field. In the opener, Sydney Gouveia pitched a complete game in a 6-1 win. In the second, the Gaels scored twice in the seventh for a 2-1 win. Monika Reichhardt delivered a walk-off RBI infield single.
LSU placed first in the six-team regional with 198.325. Cal (195.700) finished fourth and San Jose State (193.950) sixth at the Minneapolis Regional, and both teams failed to advance. Oklahoma won with a 197.725.
Lady Fifty Two, the 3-to-5 favorite ridden by Russell Baze and trained by Jerry Hollendorfer, won the $30,000 six-furlong feature by three-quarters of a length over Frisco Fog at Golden Gate Fields.
Staff writer Jon Wilner contributed to this report.