Valentina Rossi, of Argentina, is the second consecutive Michigan State player to reach
the semis of the U.S. Women's Am. (Darren Carroll/USGA)

But no matter where she has slept or what outfit she has donned, the 20-year-old from West Columbia, S.C., keeps finding a way to extend her stay at Westchester Country Club. Having survived a 12-for-2 playoff late Tuesday just to qualify for match play, the championship’s Cinderella story now has a tee time in Saturday’s semifinals after an impressive 6-and-5 quarterfinal victory over Emily Mahar, of Australia, on Friday.

Castle, who has battled a rib injury most of the summer, was 5 up at the turn and cruised home from there. She is bidding to become just the third No. 63 seed to win a USGA championship since seeding began in the mid-1980s. Clay Ogden (2005 U.S. Amateur Public Links) and Steven Fox (2012 U.S. Amateur) are the two previous No. 63 seeds to claim titles. No 64th seed has ever won a USGA championship.

“I spent three nights in a hotel and now I’m staying at a friend’s [house] on an air mattress,” said Castle of her accommodations.

As for the outfits, she added: “I actually didn't go buy any. I kind of just mixed and matched. My teammate [Marissa Wenzler, who lost in the Round of 32] wore this [Thursday], so I didn't wear it, so now she's not here so I was like, OK, this is my last full outfit. Tomorrow I’ll have to mix and match.”

Her game on Friday was well coordinated. Castle, who qualified for the 2021 U.S. Women’s Open, broke ahead with four consecutive wins from the third hole and added a winning par on the eighth hole. Mahar, who also played at The Olympic Club in June, then got married a week later, birdied the 292-yard 10th to get one hole back. But after rallying to win her first two matches of the week, the Virginia Tech senior ran out of comebacks. Jensen closed her out with winning pars on 11 and 13.

“I didn't realize I won,” said Jensen. “I thought we were going to the next hole after [No. 13]. That's how out of it I was. She was ready to hug me. I’m like, right now?”

Joining Castle in the final four are world No. 2 and reigning NCAA champion Rachel Heck, 19, of Memphis, Tenn., her semifinal opponent; University of Arizona All-American You-Chiang (Vivian) Hou, 20, of Chinese Taipei; and Michigan State sophomore Valentina Rossi, 20, of Argentina.

Heck, a rising sophomore at Stanford University who rallied from two down with two to play to defeat Brooke Matthews in 19 holes in Thursday’s Round of 16, eliminated Purdue University sophomore Kan Bunnabodee, 19, of Thailand, 3 and 2. Hou ousted high school sophomore and No. 61 seed Cara Heisterkamp, 15, of Westlake, Ohio, 4 and 3, while Rossi won her third extra-hole match of the week, defeating Stanford junior Brooke Seay, 20, of San Diego, Calif., in 19 holes.

Heck, the third player to sweep conference, regional and NCAA individual honors in women’s college history, shook off the feisty Bunnabodee on the back nine after tying the match with a birdie on the par-5 ninth. Heck played 3-under-par golf – with match-play concessions – over the final seven holes, including a birdie 2 on the 201-yard 16th hole. Two more wins and Heck can join Vicki Goetze (1992) as the second player to win the NCAA and U.S. Women’s Amateur titles in the same year.

Rossi ripped a drive on the first extra hole, the 294-yard 10th, then executed a deft pitch from 60 yards out to 6 feet for a winning birdie (Seay had already three-putted for bogey). The Argentine is vying to become the first first left-handed female USGA champion not from the state of Indiana (Erica Shepherd and Julia Potter-Bobb); no left-hander has ever won the Women’s Amateur.

Hou, looking to join Jim Furyk (U.S. Senior Open) and Annika Sorenstam (U.S. Senior Women’s Open) as 2021 USGA champions from the University of Arizona, won three of the first six holes against Heisterkamp. The 2020 Women’s Golf Coaches Association Freshman of the Year closed out the high school sophomore with a birdie on No. 15.

What’s Next

The semifinal matches will take place on Saturday at 1:15 p.m. and 1:30 p.m. EDT and will be broadcast live on Golf Channel from 2 p.m. to 5 p.m. EDT. Sunday’s 36-hole championship match will begin at 8 a.m., with the second 18 starting at 1:30 p.m. Golf Channel picks up the coverage at 2 p.m.

NOTABLE

Semifinalists earn a two-year exemption to the U.S. Women’s Amateur. The 122nd championship will be staged Aug. 8-14, 2022, at Chambers Bay in University Place, Wash. The 123rd Women’s Amateur is scheduled Aug. 7-13, 2023, at Bel-Air Country Club in Los Angeles, Calif.

By advancing to the quarterfinals, Heisterkamp, is exempt into the 2022 U.S. Girls’ Junior at The Club Old Stone in Bowling Green, Ky.

Two of Heisterkamp’s teammates at Magnificat High School in Rocky River, Ohio, Isabella Paez and her sister Avery, flew in to watch the quarterfinals, along with their golf coach, Gina Battistone.

Stanford University made up 25 percent of the quarterfinalists with Seay and 2021 Annika Award winner Heck.

Jensen Castle isn’t the only competitor making a deep run with an injury. Yu-Chiang (Vivian) Hou is playing with a torn labrum in her left hip. To rest her hip, Hou had not played a competitive event since the NCAAs in late May. This is her first U.S. Women’s Amateur.

Valentina Rossi is the second consecutive Michigan State golfer to reach the semifinals. Valery Plata reached the final four last year at Woodmont Country Club in Rockville, Md.

QUOTABLE

“Everyone is supportive. My [college] coach [Golda Borst] is in Sweden so she keeps sending me 2 a.m. text messages when she wakes up Sweden time and is like, Hey, let's go, but it's been great.” – Jensen Castle on the support she has received

“I don't know if we've played together a whole a lot. We were on the same team at Wyndham Cup. I think it's incredible that she went from the playoff to the semifinals. I was talking with my dad about how incredible that is. She's playing some amazing golf clearly and we'll have fun tomorrow.” – Rachel Heck on her matchup with No. 63 seed Castle

“I think about my injury [and] actually it went OK. I was planning to do surgery this summer, but after last season I discussed with my trainer and my [college] coach [Laura Ianello] and we just decided not to and focus more on PT (physical therapy) and doing all the exercise instead of surgery.” – Yu-Chiang (Vivian) Hou on playing through her torn labrum

“I can't believe I'm in the semifinals. It was an incredible match. As I told [Golf Channel], I played extra holes a few times, so I think that was a great advantage for me.” – Valentina Rossi after winning her third extra-hole match to reach the semifinals