Trainer needed a seven-hole playoff to beat Oregon State's Alex Moore for individual conference honors and then participated in another playoff to help the 19th-ranked Trojans win the Pac-10 team title.
"It was a really cool experience and something I gained a lot from," said Trainer. "I hadn't won in a while and it was fun to be in contention the whole way. I've been playing well, and it feels great to do it on this stage."
Stanford, ranked No. 21, placed fourth at the tournament, five strokes behind USC and No. 22 Oregon, which matched 1,415 scores after regulation play.
Stanford sophomore Andrew Yun, who was named to the U.S. Palmer Cup team last month, finished fourth and senior Steve Ziegler was 11th among individuals.
For many Pac-10 teams, the postseason is just getting started. The Cardinal will find out where it goes for NCAA regional play on Monday, when the announcements are made on NCAA.com.
Stanford reached match play of the NCAA tournament after winning a three-way playoff with San Diego and Arizona State. The Cardinal lost, 4-1, to Oklahoma State in the first round.
The Cowboys are currently the top-ranked team in the nation and host the NCAA championships at the Karsten Creek Golf Course in Stillwater beginning May 31.
David Chung recorded the Cardinal lone victory, winning on the final hole, 1-up.
Stanford won the national title in 2007 and finished second to UCLA in 2008. Augusta State is the defending national champion.
Yun has been Stanford's most consistent golfer this season, finishing among the top 10 in seven of 10 events. He was the Cardinal top golfer in nine events, with senior Sihwan Kim leading the way when Stanford finished second at the Gifford Collegiate Championships, the team's best finish of the year. Stanford also finished tied for second at the Prestige at PGA West, where Yun earned medalist honors.
Kim has not appeared in Stanford's lineup since the USC Collegiate Invitational and has played in just three events.
Ziegler recorded his best finish at the Pac-10 tournament, with his first-round 69 a season best.
Chung, who was among the top 10 at the Gifford Collegiate, also shot a round of 69 at the conference tournament.
Cameron Wilson has appeared in the top 10 at the Prestige (fifth) and Gifford (ninth).
Trainer played the 18th hole a total of nine times, all at par, on the final day of the conference tournament.
"It feels great to win Pac-10s, that's for sure," Trainer said. "It was cool we could crush them (Oregon) in the playoff so we wouldn't have to do it again. I didn't want to go back on 18 again."
Trainer finished at 5-under 275 (68-68-69-70) for his third straight top-5 finish and first title as a Trojan.
Trainer actually lost a chance to win the tournament in regulation, but he drove into the left rough on the par-5 16th hole. He wound up with a bogey, which ultimately cost him the lead. But, it could have been worse. He came within 10 seconds of losing his ball on the 16th, which would have cost he and the Trojans a chance to win.
Mountain Pacific Sports Federation tournament champion Stanford, currently ranked sixth in the nation by the IWLCA, will learn its NCAA tournament fate Sunday at 4:30 p.m. with an announcement on NCAA.com.
The seven-time defending MPSF champion Cardinal (16-2) is hoping to host a first-round match in the 16-team field, though they are 13th in the RPI ratings.
Stanford, making its second straight trip to the NCAA, overcame a seven-goal deficit to beat Oregon, 12-10, in the MPSF championship final.
Conference Player of the Year Leslie Foard scored on three of her five shot attempts to lead the comeback.
Freshman goalkeeper Lyndsey Munoz, who came on after Stanford fell behind 7-0, was named the tournament MVP.
The Cardinal, who won 15 of 20 last year, fell to James Madison, 9-8, in the first round of the 2010 tournament after holding a second-half lead.
Women's water polo
Stanford, despite losing in the semifinal round of the Mountain Pacific Sports Federation tournament, was awarded the top seed for the NCAA Championship to be held May 13-15 at the Canham Natatorium, in Ann Arbor, Michigan.
The top-ranked Cardinal (25-1) will meet the winner of a play-in game on the first day. SCIAC champion Redlands and MAAC champion Iona College meet Saturday at the Greenwich Family YMCA in Greenwich, Connecticut for the right to play Stanford.
Automatic qualifiers included UC Irvine, Indiana, California and UC San Diego. Stanford is joined by UCLA and USC as at-large teams.
The Bruins handed Stanford its only loss of the season last Friday. UCLA lost to the Bears in the title match. The Bruins also knocked off USC in the MPSF tournament.
California (24-4) was named the second seed and will meet No. 7 UC San Diego (17-18) on May 13 in the first game of the championship at 3 p.m. The next game features No. 3 seed UCLA (24-6) and No. 6 seed Indiana (25-11) at 4:30 p.m. Stanford will face the winner of the play-in game in the third game of the day at 6 p.m. The final contest of the night will pit No. 5 seed UC Irvine (21-8) against No. 4 seed USC (18-6) at 7:30 p.m.
Sophomore two-meter Annika Dries was named MPSF Player of the Year on Tuesday, one of six Stanford players honored on the all-MPSF teams.
Dries, who was also named to the first team, ranks third in the MPSF with 2.23 goals per game, and tops the Cardinal with 58 goals. She also joins Ellen Estes (1998) and Brenda Villa (2001, 2003) in earning Stanford's fourth conference player of the year honor.
Junior Melissa Seidemann joined Dries on the All-MPSF First Team.
Stanford looks to rebound this weekend when it hosts Washington for a three-game Pac-10 series beginning Friday at 6 p.m.
The Cardinal (6-9, 22-15) is in seventh place in the Pac-10 standings, a game behind USC and 1 1/2 games behind Arizona. Washington (4-11, 13-27) rests in last place, two games behind Stanford.
The Cardinal lost two of three to host Arizona State last weekend but came back to beat San Jose State, 3-1, in a nonconference game Tuesday.
Stanford (7-7, 34-11) travels to Oregon (7-7, 35-11) for a three-game Pac-10 set that features two of the five teams currently tied for third play in the conference standings.
Arizona State (11-3, 44-5) has a two-game edge over second-place California at the top of the standings.
The Cardinal beat Santa Clara, 12-0, Tuesday night in a nonconference game after taking two of three from Washington last weekend.
Stanford has announced a freshman class for the 2011 season that features five recruits with youth national team experience, two state players of the year, a two-sport Stanford athlete, and a pair of Bay Area natives.
The six-member class strengthens a program that has completed two consecutive undefeated regular seasons, won two consecutive Pac-10 titles, reached the past three NCAA College Cups, and the past two NCAA championship finals.
The class is comprised of forward Alex Doll (Bethesda, Md.), midfielder Hannah Farr (Hillsborough), midfielder Lo'eau LaBonta (Rancho Cucamonga, Calif.), midfielder Haley Rosen (Rolling Hills, Calif.), defender Lauren Schmidt (San Martin, Calif.), and forward Chioma Ubogagu (Coppell, Texas).