CHARLESTON, S.C. -- The first set against Romania’s Gabriela Lee ended in a tiebreak, where Ashlyn Krueger took complete control by winning all seven points. There was a deft swinging volley winner, an unreturnable serve and, as luck would have it, a netcord that neatly dropped in.

It was a microcosm of her recent, dramatic rise in the Hologic WTA Tour rankings. The 19-year-old American defeated Gabriela Lee 7-6(0), 6-3 and advanced to a Wednesday second-round match at the Credit One Charleston Open before eventually falling to finalist No.4 seed Daria Kasatkina.

Krueger wouldn't be down and out for long. On Sunday, she teamed with fellow American Sloane Stephens to defeat Ukraine sisters Lyudmyla and Nadiia Kichenok 1-6, 6-3, 10-7 in the doubles final.

Memo to the rest of the field: Krueger is coming for you.

She’s ranked No.73 -- No.31 Linda Noskova, 19, and No.38 Mirra Andreeva, 16, are the only younger players ahead of her in the rankings. Now that Coco Gauff has turned 20, Krueger’s the only teenager in the American Top 20. In fact, you have to go down to No.183 Robin Montgomery -- also 19 -- to find someone younger.

Krueger is just a shade under 6-foot-1, but unlike many big hitters from the United States, she’s unnervingly comfortable on clay.

“I mean, I just think it’s fun,” she told wtatennis.com in Charleston. “Diversity, it’s what the game’s all about. It gives me more time to set up for my shots, which is really nice. And I’ve learned to move on it better.”

It started at the Brookhaven Tennis Academy in Dallas, where coach David Anderson insisted that she play every other day on clay. Krueger learned how to harness her weapons, the serve and the forehand, and wait for the proper openings. Her smooth, long, flat, deep shots are going to prove increasingly problematic for opponents at this elite level.

She knew by the age of 11 she wanted to be a professional tennis player, when she saw five-time Grand Slam champion Maria Sharapova succeeding at the highest level. “She had the same body type as me,” Krueger said. “When you see someone that looks like you, it’s really important. I saw her and said, `I want to do that.’”

Tennis Channel analysts Lindsay Davenport and Chanda Rubin -- both successful former players from the United States -- discussed her merits for the better part of two hours on Tuesday. 

Davenport’s description of “easy power” was particularly apt, an attribute the three-time Grand Slam champion herself possessed.

And though movement, understandably, is not her greatest asset, under coach Michael Joyce, Krueger has shown aptitude for moving forward. She won a number of points at net.

“Yeah,” Krueger said, “I get a lot of those short balls moving forward. The girls nowadays are so physical, and they can rally from the back like crazy, so I have to stay ahead. I think the short balls coming in is the way to do it.”

Winning the title last year in Osaka accomplished a big career goal, Krueger said. But she doesn’t really look at the rankings.

“One goal at a time,” she said, “that’s why I got to where I’m at so fast -- because I didn’t think ahead too much. That’s because I’m an overthinker. People around me kept me grounded, and I keep plugging away.”

Her short-term goals are simply to go deeper in the tournaments that offer the most points. She’s played three US Opens (two wild cards and a qualifying berth) and lost in the first round each time. At this year’s Australian Open, Krueger’s ranking earned her a spot in the main draw for the first time -- and the result was the same.

“Getting my first Grand Slam win under my belt is a huge goal,” she said. “Hopefully, I can do that at the French.”

Rubin placed her ranking potential in the “Top 30, Top 20 -- or even further,”

What does she need to work on?

“Getting things sharper, learning to adapt to every player, just a little bit quicker.,” Krueger said. “You see the people in the Top 10, Top 5 -- Top 20 -- they’re very good at adapting, and they’re very mentally strong.”

Even at a young age, Kruger is exercising the right-hand side of her brain -- something that should help her balance life going forward. She enjoys painting, reading poetry and admits to being a bit of a foodie. If she wasn’t playing tennis, she’d probably be pursuing a career as an esthetician, a skin-care expert. She’s not one to watch television shows via streaming. She’s a movie person, partial to science fiction. “Interstellar” is her favorite.

And she’s unfailingly polite.

An hour after her match, and a congratulatory victory handshake, she apologized for being sweaty -- an occupational hazard. Going forward, it will be a good problem to have.

Champions Reel: How Ashlyn Krueger won Osaka 2023