(CNN)In tennis, it’s beyond difficult to transition from teen prospect to grand slam winner. Roger Federer, Serena Williams, Rafael Nadal and Maria Sharapova are the high-profile exceptions rather than the rule.
You don’t need to tell that to Americans Taylor Townsend or Kristie Ahn, either, but here they are into the fourth round of a major for the first time many years after being tipped for glory.
Townsend continued her winning ways over Romanians when the qualifier defeated Sorana Cirstea at the US Open on Saturday 7-5, 6-2, charging the net in similar fashion that earned her a stunning victory over Wimbledon champion Simona Halep.
Later, wildcard Ahn overcame a leg injury to down the error-strewn 2017 French Open champion Jelena Ostapenko, 6-3, 7-5.
They are the first US wildcard and qualifier duo to make the last 16 at Flushing Meadows since wildcard records began being kept in 1987, according to the USTA.
Townsend reached the top of the junior world in 2012 but is seeking her first title — or semifinal — at the highest level. Her win over Halep — when she went to the net 106 times — was her first in 11 tries against top-10 opposition.
Four years ago, her year-end ranking sunk to 304th.
“It’s been, like, a really long journey,” Townsend said after beating Halep, a journey that included being stripped of travel funding by the USTA because of, it said, her weight. “You flood with emotions of the things you’ve been through, positive, negative. Just to be able to, like, get over the hump, it’s such an amazing feeling because, like, I mean, after Wimbledon, I was devastated after I lost to (Kiki) Bertens after having a match point. That, like, woke me up out of my sleep.
“I put my head down and just worked really hard and just tried to, like, take the positives away from it, just continue to press forward.
“I think for so long that’s been kind of my whole thing, is just continue to press forward and just realize that I belong on this level. You know what I mean? I’ve had a lot of people doubting me being able to break through, quote unquote.”
Bianca Andreescu, currently a teen phenom herself, is Townsend’s next challenger after the Canadian beat last year’s Australian Open champion, Caroline Wozniacki, 6-4, 6-4.
Ahn back to US Open after a decade
Ahn, meanwhile, played the US Open as a 16-year-old qualifier in 2008, acquitting herself well in a first-round loss to then seventh-ranked Dinara Safina.
But instead of turning pro, as she wanted to, the parents of Ahn — who was born within walking distance of the US Open — wanted her to go to college and get an education.
She did just that at Stanford in California, excelling on the tennis team while earning a degree in science, technology and society in 2014.
That’s when she made a deal with her dad, Don.
“She said, ‘Dad, you didn’t give me a dime for college tuition, so why don’t you support me for three years? I wanted to play tennis, that was my dream, and you cut it short,'” Don told the New York Times. “I was the person who said to go to college. We shook hands. That was the deal.”
But when the three-year deal ended in 2017 — when Ahn ended the season ranked 106th — she wanted to keep playing, which didn’t please her parents, according to the Times.
The 27-year-old can fund herself for a while to come given the $280,000 she has pocketed by making the fourth round. It looked dicey for Ahn when she took a medical timeout for a left leg injury in the second set, though still got over the finish line.
She had never won a grand slam match prior to this week.
Ahn likely won’t be overawed Monday in meeting the 25th seed, Elise Mertens of Belgium, since she triumphed in their clash in San Jose in straight sets at the start of August. That would take her earnings in New York to $500,000.
Nadal comfortably advances
Nadal progressed in straight sets Saturday, 6-3, 6-4, 6-2, over South Korea’s Hyeon Chung.
The bespectacled Chung is hoping all his injury problems are behind him but one round after edging Fernando Verdasco in five sets, he couldn’t get the better of another, more prolific, Spanish left-hander.
Up next for Nadal will be either No. 22 seed and 2014 champion Marin Cilic of Croatia or John Isner, the No. 14 seed, of the US.
“The key is play well,” Nadal said of the prospect of facing either player. “That simple. If I am playing well, I going to have hopefully my chances to return a couple of points and give me chances.
“I know against big servers like them, chances are not a lot, so you need to be ready to expect a very tough one. But I need to be focused with my serve, as always. I need to be ready to accept the challenge that brings the competition in days like these ones. And I hope to be ready to play my highest level, because that’s what I going to need.”