WASHINGTON, D.C. -- Hard as it may be to believe, Emma Raducanu is still only 22 years old.

She has only a single career title to her name, but it was a big one -- the 2021 US Open, as an 18-year-old qualifier. Since then, it’s been a difficult, highly scrutinized journey as her body hasn’t dealt well with the physical demands of the game.

Washington, D.C.: Draws | Scores | Order of Play

But after three separate surgeries in 2023 and an eight-month hiatus, Raducanu has gradually begun to find her groove.

On Tuesday, she took another step with an impressive 7-6(4), 6-4 victory over No. 7 seed Marta Kostyuk at the Mubadala Citi DC Open. It was a draining match that required nearly two hours.

Raducanu advances to a second-round match that, if it doesn’t break the Internet, will certainly have social media abuzz. She’ll face former World No. 1 Naomi Osaka, who was a 6-2, 7-5 winner over Yulia Putintseva on Tuesday.

If it feels like a fresh, exciting matchup, that’s because it is. Surprisingly, Raducanu and Osaka have never played.

“I think it’s a great match for a lot of spectators, which is great to be a part of,” Raducanu told reporters. “I felt the same way when I played Aryna [Sabalenka] at Wimbledon. That atmosphere was unbeatable for me. I think all the exposure I get to these top opponents … she’s won four Grand Slams, so an incredible achievement and incredible career so far. 

“And she’s been playing really good tennis this year. Yeah, it will be a great test of my own game and myself.”

From 2018 through 2021, Raducanu and Osaka won three of the four US Open titles. And so, these are two players who have had the rare privilege to experience the thrill of victory at the highest level -- and struggled in recent years to recapture it.

Osaka, 27, missed the entire 2023 season to focus on the birth of her first child. Since returning, she’s 37-27, a respectable .578 winning clip -- respectable unless you carry the memories and expectations of a four-time Grand Slam champion.

Osaka's record this year is now 21-10, but Osaka has expressed frustration several times. Most recently after falling in the third round at Wimbledon to Anastasia Pavlyuchenkova, more forcefully after losing in the first round of the French Open to Paula Badosa.

“As time goes on, I feel like I should be doing better,” she told reporters in Paris. “I hate disappointing people.”

But after the red clay and green grass of Europe, Osaka is thrilled to be back on more familiar turf -- the surface that delivered all four of those Grand Slams.

Against Putintseva on Tuesday, Osaka was solid, firing eight aces, winning 89 percent of her first serves and scoring four breaks of serve.

Osaka acknowledged she felt a certain level of comfort returning to hardcourts: “Honestly, yes,” she said. “But I also had a realization the other day that I have to be a little bit more confident in myself while also not putting pressure on myself, so it’s a little strange. I think I’m the type of person that, I always feel like everyone else is really good, and sometimes that puts a lot of doubt in myself.

“The other day I was trying to tell myself that I won a couple of Slams on this surface for a reason, so I need to believe in myself a lot more. I’m trying to see where that mentality takes me.'

For now, it has taken her across the net from Raducanu. “I’m always a person that loves when people are entertained,” Osaka said of the upcoming match. “So I would say I'm excited about it. I’ve never played her before, so for me, that’s something really cool too.

“Because I have seen her, I guess when she first did well at Wimbledon before she won the US Open, like moments like that, and I knew she was a good player. So I guess for our paths to finally cross is really cool.”

As for Raducanu's Tuesday match, No. 27-ranked Kostyuk is the highest-ranked player the Briton has beaten since May, when she defeated No. 17 Daria Kasatkina in the first round of Strasbourg.

The first set was a fabulous near-dead heat, everything the matchup had promised coming in. Kostyuk, an undeniably talented player, held the upper hand for much of the way, coming within two points of winning the set on two different occasions.

Both players managed a single break of serve and arrived at the tiebreak. Kostyuk, under relentless pressure and hindered by a double fault, immediately fell into a 4-0 hole. But just as quickly, following a pair of forehand winners, it was back to 4-4.

But the comeback effort may have cost her. Kostyuk donated a wild mishit, and Raducanu followed that up with some stellar defense and a laser backhand winner down the line. On the first set point, Kostyuk overcooked a forehand return and Raducanu had escaped.

How tight was it? In the excruciating heat, both players won 48 points. That exhausting frame consumed 70 minutes. Kostyuk would later sit in her changeover chair with a bag of ice atop her head.

The momentum continued in the second set, when Raducanu won the first three games. Kostyuk, with some spirited play, leveled the field and it was 4-4.

But Raducanu held serve for 5-4 when Kostyuk missed a backhand, then broke serve for the win, converting her second match point when a Kostyuk forehand sailed wide.

Raducanu converted just one more break point than Kostyuk in the match -- and that made the difference.