PARIS, France - No.13 seed Madison Keys dominated No.21 seed Naomi Osaka to become the first player to book a place in the second week of Roland Garros, powering her way through the third-round clash 6-1, 7-6(7) in one hour and 23 minutes.

It is the second time the American has made the fourth round in Paris following her 2016 run, when she defeated Donna Vekic, Mariana Duque-Mariño and Monica Puig before falling to Kiki Bertens; and the third time in as many meetings that she has gotten the better of Osaka. In their first meeting, in the third round of the 2016 US Open, the Japanese player led 5-1 in the deciding set before losing 7-5, 4-6, 7-6(3); since then, she has now lost four consecutive sets to Keys.

In a match-up between two players who favor big serving and first-strike tennis, it was the US Open finalist who was landing her blows more effectively. Four service winners set the tone in the first game: though Keys' ace tally today was a modest three, she was able to rack up a large number of free points as Osaka was unable to keep her returns in play. Consequently, Keys would not face a single break point in the first set.

The Indian Wells champion, by contrast, was laboring not only to deal with her opponent's delivery, but with her own. Osaka was broken in her first service game on a double fault, and an unfortunate 39% first serve percentage in the first set enabled Keys to cheerfully tee off on a number of returns for clean winners; it would only creep up to 56% in the second set.

Whereas the youngest player remaining in the draw only got on the board after a multi-deuce struggle in a 28-minute first set, Keys' level continued to rise. The 2016 Rome runner-up displayed more awareness of court geometry and clay movement than Osaka, working the angles before slamming winners, particularly on the backhand down the line.

"I have had good results on clay," smiled Keys afterwards. "I think it's more my own mentality on clay. I feel like a lot of times I get too passive or too aggressive, and it's finding that middle ground where I'm not playing a different way than I like playing tennis."

The match began to narrow in the second set when, up a set and a break, errors began to creep into Keys' game: from nine in the first set to 19 in the next. Though the 23-year-old staved off her first three break points of the match - two, naturally, with service winners - to extend her lead to 3-1, she was unable to dig herself out of another 0-40 hole in her subsequent service game. Osaka, suddenly hitting freely, proceeded to win 10 consecutive points, holding to love with a delightfully spun volley to lead 4-3.

"I just thought to myself that, even if I lose, I don't want to have any regrets or anything, and I want to try to keep fighting until the last point," said Osaka. "I feel like there was a moment where maybe the me from before, the younger me, would have just accepted that I was losing. But now I'm not sad, because normally I would be very sad at this point."

With the set hanging in the balance at 30-30, Keys went back to basics, snuffing out her opponent's momentum with a forehand winner and yet another unreturned serve. But she would unravel again in attempting to serve out the match, spurning a match point with one of several groundstrokes that sailed over the baseline in this game.

However, Keys did not have any regrets about this game. "I think even serving at 5-4, I was actually, for the most part, happy with most of my shots - I feel like I just missed some of them," she said. "After that, it was just, OK, let me just focus on my game, make all of the balls that I can. And then I felt like I had to just really balance making the ball when I didn't have the right one, and then once I had the right one going for it and still trusting my game."

Suddenly, it was Keys needing to battle to stay in the set. Serving at 5-6, the Stanford champion broke out some unexpected variety in the form of a reflex volley and superb dropshot to force a tiebreak; trailing 1-4 there, she drew on groundstroke power to claw her way back, firing three scorching winners to pull back to 4-4.

Keys would still have to fend off two set points - one after Osaka pulled the trigger on a forehand too soon, sending it into the net, and another with a service winner. With the match on a tightrope, though, it was Osaka's subpar serving that once again proved crucial, though. The 20-year-old would only serve three double faults over the course of the match - but two of them have been down break point and the third, sadly, was down match point.

Afterwards, the former World No.7 attributed her win to her experience. "I think we have very similar games - I obviously like playing against someone who has pace," she explained. "But even seeing how she raised her level in the second set was a lot different from the last time we played each other, so you can tell that she's definitely getting better and better and making smarter decisions. So I think luckily I'm still a little bit older, so pulled out the veteran moves today."

The result means that while Osaka must wait to score a maiden Top 20 win on clay, Keys notched up a fourth following Li Na at Madrid 2013 and a double whammy over Petra Kvitova and Garbiñe Muguruza at Rome 2016. She could have the chance to add another in the next round: Keys will bid to complete her set of career major quarterfinals against either No.4 seed Elina Svitolina or No.31 seed Mihaela Buzarnescu.