Fittingly, the Rainbow Wahine’s first women’s golf championship in 19 years was played out with thunder and lightning in the background.

A roster jammed with underclassmen the last two years is now top-heavy with five juniors and a senior. They put it all together Tuesday to win the storm-shortened Hobble Creek Fall Classic in Utah, on coach Lori Castillo’s birthday.

Castillo, a Hawaii Golf Hall of Famer in her eighth year at the University of Hawaii, described it in typically analytical terms.

"We tried to play the right strategy on each hole," she said, "and sometimes we pulled it off."

One of her juniors is 2011 state high school champ Eimi Koga, who won her first tournament as a Wahine. The Moanalua graduate’s score of 1-under-par 141 was two shots ahead of runner-up Raquel Ek, another UH junior.

Ek was also second in last season’s final tournament, helping Hawaii to a runner-up finish at the Big West Championship and its lowest 54-hole score in history (887). This season, Hawaii hosts the conference championship at Kapalua Bay in April.

The addition of Koga, Ek’s relentlessness, a breakthrough seventh-place performance by Kauai High alum Daezsa Tomas and yet another Top 30 from Izzy Leung lifted Hawaii to a 583 score as it beat out BWC members Cal State Northridge and Cal Poly. Leung was the medalist in last year’s season opener and has been Hawaii’s top finisher in 16 of her 20 starts.

The second round was suspended Monday because of darkness. Teams finished it Tuesday before rain washed out the final round. A UH team that often struggles to break 300 would stay at the top of the leaderboard, for the third time in program history.

"I always felt we had this potential, but it never came together at a tournament where we played well enough to win," said Ek, last year’s most improved after cutting her stroke average by more than a shot. "This time we all came through so it was pretty cool."

Koga returned home from a two-year honorable-mention All-America sojourn at the University of Washington with an even more dynamic game and not-nearly-so-lean look. Most fear the "Freshman 15," but the formerly scrawny Koga embraced it.

"One of the biggest changes is that I gained 30 pounds," said Koga, now all of 130. "I worked out a lot, gained a lot of yardage. It changed my game dramatically. I came back home and everybody said I looked a lot better, quite normal now. That was the plan. My dad wanted me to gain."

Castillo was happy to have her home, a decision Koga made so she could train more with her father Yukio, who also coaches younger daughters Jennifer and Ashley.

Eimi was the only sister born in Japan and she has become fluent in the language. That helps immensely now as she is in the midst of trying to qualify for the Japan LPGA. She and former UW teammate Cyd Okino, a Punahou graduate, are both headed to the second stage of JLPGA qualifying in November.

"Having a strong player like Eimi helps tremendously," says Castillo, who has given her full support to whatever Koga decides to do if she qualifies for JLPGA. "We are at least 25 percent better. We also have five juniors out of nine players, so we have experienced players who have proven they can help lead the others.

"This will add more confidence.The players are already close, like sisters, which is nice. Now they can lift up and encourage each other more. I think the others feel more challenged than threatened. They also know they have games and can compete."

If they didn’t before, they do now. Especially with Koga, who won a bronze medal for the U.S. at this summer’s World University Games.

"It’s really good she has come to the team and right away she was just a positive addition," says Ek, who met Koga at Junior Worlds when both were 16. "She is always happy, smiling, really outgoing. She blends in very well. It seems like she’s been here the last two years, not three weeks."

Hobble Creek was hosted by Utah Valley, which has four Hawaii players (Cassandra and Isabella Lesa, Kalea Heu and Kaylee Shimizu). Punahou graduate Kristin Le, now at Santa Clara, tied for 10th. Eastern Washington’s Kirsten Ishikawa and Kimberlie Miyamoto were both in the Top 35.

Hawaii will host a "Nine and Dine" Golf Tournament Nov. 9 at Kaneohe Klipper. The nine-hole scramble, followed by a meal, has a 2 p.m. shotgun start. Cost is $400 for a four-person team, or $100 each. All nine Wahine will play with the teams in the fundraiser. Call 965-4333 for more information.