SEATTLE — Their friendship first sprouted on the other side of the world with three letters across their chests, a bond between two fiery future women’s basketball stars that now takes center stage nearly four years later.

It was during the 2019 summer that USA basketball first united Caitlin Clark and Hailey Van Lith, then both uncommitted high school stars eyeing intense basketball battles before their collegiate careers commenced. They roomed together. They competed together. They won gold together in Thailand.

Now, they’ll share Sunday’s spotlight together.

With a Final Four berth on the line — Iowa and Clark hunting the program’s first since 1993; Louisville and Van Lith shooting for the school’s fifth since 2009 — these two have taken center stage in Seattle. Although all friendly talk will subside between the two come 8 p.m. inside Climate Pledge Arena, both Clark and Van Lith can appreciate what the other has done in creating this magical moment.

“We understood (during USA basketball) that we’re going to see each other in college at some point,” Clark said, “with the schools we were going to and the potential and the type of (NCAA Tournament) runs we want to make and the dreams we had.

“It’s fun because you build relationships with them, and then you get to go and compete against them. I think it’s really fun and a special dynamic.”

To truly bring this connection full circle, the coach on that championship-winning U19 squad will also be in the building — game-planning against Clark while hoping Van Lith is who ultimately shines brightest.

Louisville head man Jeff Walz could see the elite potential in both his future player and future foe when he coached them for nearly two months during that 2019 summer. Clark, Van Lith and Connecticut star Paige Bueckers were the only active high schoolers to crack the roster, which was set in May ahead of training camp in early July and the actual event in late July.

Instantly, Walz and Clark clicked with similar personalities — fiercely intense amid the basketball action, yet goofy and full of dry humor outside the lines. It’s part of the reason Walz and Clark have remained in touch years after that thrilling summer.

One of Walz’s recent texts to Clark offered a microcosm of their relationship.

“Caitlin makes that shot (at the buzzer) against Indiana to win, and I’m sure her phone was just blowing up,” Walz recalled. “I sent her a simple text that said, ‘It hit the rim. It wasn’t all that impressive.’ And within 45 minutes. she was like, ‘Why doesn’t that surprise me from you?’ With a big smiley face.

“She’s fantastic.”

The same can be said about Van Lith, the Cardinals’ catalyst who racked up first-team all-ACC and AP all-American honorable mention honors this season. She’s the engine that makes Louisville go and isn’t afraid to let you and others know about it.

Sound familiar?

“I appreciate that in her more than anything,” Clark said. “I really admire that passion, that competitive spirit, that fire that she plays with. I think a lot of people should play with that. That’s what makes her team go, when she’s fiery and competitive. She plays with that emotion because she wants to win more than anything.”

Expect that intense emotional concoction Sunday as Clark and Van Lith try to guide their squads along. Both have been fantastic this March Madness, scoring 20-plus points in all six of their combined NCAA Tournament games to get here.

Slowing either will require elite defensive efforts. All-ACC defensive team selection Mykasa Robinson will likely guard Clark much of the way. Iowa will almost certainly throw a combination of Gabbie Marshall and Kate Martin at Van Lith. Whichever side can maintain composure while the opposing star inevitably pours in buckets could decide who is dancing to Dallas and the Final Four.

“Elite offensive players, they’re never going to let up,” Martin said. “They’re always moving, and they’re going to try to capitalize in big moments — just like Caitlin does and every great player would. So getting stops when you can and limiting touches, getting deflections on balls, diving on the floor for a loose ball, whatever you’ve got to do that you can control to limit players like that.”

Clark and Van Lith have certainly fit that mold for a while.

“Caitlin is a great person off the court, really funny, great sense of humor,” Van Lith said. “I have supported her through her college career and she’s supported me through mine. She’s gotten better every year. She’s gotten better since I played with her on Team USA. So she’s a great player and great person.”