Before the US Open began, Australian John Millman joined former World No. 1 Andy Murray for a practice session inside Arthur Ashe Stadium, the biggest tennis-only stadium in the world. After their hit, they tried launching 20 to 30 balls toward the scoreboard at the top of the stadium. The Budapest finalist had no luck, missing to the right. The 6’0” right-hander didn’t necessarily expect to be back on that court for a match at the year’s final Grand Slam.

But now, that looks like a near certainty. The Aussie defeated Kazakh Mikhail Kukushkin on Saturday to reach the fourth round at a major for the first time. His reward? A meeting against five-time champion Roger Federer.

“I’ve always had confidence with my game and the longer my career has progressed, the more comfortable I’ve felt,” Millman told ATPWorldTour.com. “But to be honest with you, coming into this tournament, my expectations were pretty low. So maybe the time I thought I was going to be playing on Ashe was that practice session I had with Andy.”

Millman was forced to withdraw from his first-round qualifying match in Cincinnati in August due to a back complaint, and he lost in the first round at Winston-Salem the week before Flushing Meadows. But adversity is nothing new for the 29-year-old. In a way, it’s been intertwined in his journey.

Early on in his career, Millman underwent a shoulder repair and he would need a shoulder reconstruction in 2013. Last February, he underwent groin surgery. That latest operation was a devastating blow considering that in 2016, Millman had ascended to what was then his career-best ATP Ranking of No. 60.

“[I had] a lot of moments of doubt, as there has been every time I’ve come back from surgery with a couple shoulders and the groin, a lot of moments of doubt. It’s tricky, because tennis on the men’s side at the moment — I only mention the men because I’m on the men’s tour — it’s so competitive right now,” Millman said. “There are so many good players, and sometimes we don’t see that because we see all our top players a little bit. But you don’t really understand the depth that there is out there and if you’re not fully functioning and firing on all cylinders, you won’t get back to the level and that’s a tough feeling. That’s tough to fight back from.”

But like he always has, the Brisbane native has chipped away. Last October, Millman dropped to World No. 218. If nothing else, his focus was on his health, preventing injuries, and maintaining a strong diet. Less than 11 months later, he’s in the second week of a Grand Slam and poised to surpass his career-high ranking of No. 49.

Watch Interview With Millman After A Recent ATP Challenger Tour Victory:

This comeback has been especially difficult, as the Aussie bases much of his game on his movement. And what does a groin injury inhibit? Movement.

“I like to extend points and really use my legs to keep myself in the battle, and that’s tough. But really happy that I managed to get back,” Millman said. “I had a great surgeon, a great team around me that really helped me out and now I’m back here and playing some of my best tennis. It’s a satisfying feeling.

“I’ve gotten better as this tournament has progressed and I feel as if I’m playing some good tennis and I really do feel I deserve my spot there. You have to win three matches, I’ve done that, and I’ve given myself an opportunity to put myself in a big match on the big stage.”

When Millman takes the court against Federer on Monday, there will be a sense of pride, for sure. But the Aussie says that it’s not all about him. It’s about everyone who has supported him through his highs and his lows. He bears all of those people in his mind when he goes out to do battle, and Millman will try to make them proud.

Read: Fantastic Federer Dismisses Kyrgios

Millman has played the second seed once before, pushing the Swiss star to three sets in Brisbane three years ago. And if they are placed on Arthur Ashe Stadium, keep in mind that the last time Millman was on that court, he was thinking about launching balls toward the sky, not playing a match. “If you can get the win on Ashe and the adrenaline’s pumping, maybe you can touch it,” he said.

It’s safe to say if Millman is able to shock the world and spring the upset of the tournament, he’ll certainly give it a go.

When five-time champion Roger Federer and No. 30 seed Nick Kyrgios stepped on the court in Arthur Ashe Stadium for their third-round match at the US Open on Saturday afternoon, there seemed little doubt that it would be a hard-fought clash. Each of their three previous FedEx ATP Head2Head meetings went to third-set tie-breaks, after all.

But Federer made it clear that he is one of the leading favourites in New York, dismissing the 23-year-old Aussie 6-4, 6-1, 7-5 in just one hour and 44 minutes.

Federer is into the fourth round in Flushing Meadows for his 17th consecutive appearance, improving his record at the year’s final Grand Slam to 85-12. The Swiss star has only failed to reach the Round of 16 here once, on debut in 2000, when he advanced to the third round before losing to Juan Carlos Ferrero.

This year’s Australian Open, Rotterdam and Stuttgart champion, who is bidding to lift his first US Open title since 2008, recovered from 3-3 (0/40) down in the first set, saving four break points, before securing a crucial break of serve in the 10th game with a chip backhand return as Kyrgios attempted to serve and volley.

Federer was also dominant on serve, dropping just five points on his first delivery through two sets. He also did a good job of keeping Kyrgios from controlling play with his forehand by playing aggressively himself, hitting 51 winners to just 24 unforced errors.

While it was not the decisive blow, it became clear in the third set at 3-3 that it was simply the 37-year-old’s day. Federer sprinted forward to a ball and shoveled a forehand around a netpost for a winner — surely the shot of the day — leaving Kyrgios with his mouth wide open in disbelief.

“I was trying to tell him that the shot wasn’t that good,” Kyrgios said, smiling. “No, it was almost unreal. Almost got to the point where I wanted him to start making shots like that, and I finally got it.

“It was unbelievable. I’m probably going to place it on Instagram.”

The Swiss now leads the Aussie 3-1 in their FedEx ATP Head2Head series. Before the match, eight of the nine sets they had contested went to tie-breaks.

Federer will next face another Aussie in John Millman, who beat Mikhail Kukushkin 6-4, 4-6, 6-1, 6-3 to reach the fourth round at a Grand Slam for the first time. The Swiss was victorious in their only previous FedEx ATP Head2Head meeting, which came in a three-setter three years ago in Brisbane.

Millman will attempt to earn his first victory against an opponent inside the Top 10 of the ATP Rankings. The 29-year-old is projected to surpass his career-best ranking of No. 49 based on his performance in New York.

In the top half of the draw, only one player has cruised into the second week of the US Open without dropping a set: Juan Martin del Potro.

When Del Potro is this efficient, few can touch the Argentine’s imposing game and he continued his ruthless run on Friday. A semi-finalist last year, he has carried the momentum into the 2018 edition, barely putting a foot wrong en route to the Round of 16.

Del Potro dismissed an upset-minded Fernando Verdasco 7-5, 7-6(6), 6-3, overcoming a mid-match hiccup to punch his ticket on Day 5. He launched 41 winners, including 12 aces, while claiming a dominant 80 per cent of points on his first serve. 

“It was a really nice fight and we played three great sets,” Del Potro told ESPN following the match. “Thanks to the crowd for staying until almost 1am to cheer for me.”

The 2009 champion earned his 40th match win of the year on Friday, joining Alexander Zverev (45), Rafael Nadal (43) and Dominic Thiem (41) in the club. Del Potro is bidding to reach the quarter-finals or better in a fifth consecutive tournament, having entered Flushing Meadows on the heels of deep runs at Roland Garros, Wimbledon, Los Cabos and Cincinnati.

40-Match Winners In 2018

After exchanging breaks early in the opener, Verdasco was unable to sustain the momentum as the set hit a critical juncture. A loose service game saw Del Potro break to love for 6-5 and he would unleash a forehand barrage to snatch a one-set lead.

Del Potro earned a quick break in the second set and the rout was on. Or so it seemed. After committing just six unforced errors in the first 15 games, seven more would suddenly leak from the Tandil native’s game as Verdasco broke back and edged ahead 3-2. But with his mettle tested, Del Potro would eventually take a two-set advantage by the slimmest of margins in a tie-break. And he cruised from there, breaking early in the third and never looking back.

The match finally hit its conclusion at 12:34am, as Del Potro converted his first match point after two hours and 59 minutes.

Del Potro sets a fourth-round meeting with Borna Coric, who has dropped just one set en route to the last 16. The 20th-seeded Croatian downed Daniil Medvedev 6-3, 7-5, 6-2 under the lights on Court 17. He fired 30 winners, while converting an impressive six of 13 break chances.

A rematch of their encounter at the Next Gen ATP Finals last year, also won by Coric, the Croatian owns a 3-1 lead in their FedEx ATP Head2Head series. He ended Medvedev’s win streak at eight straight, following the Russian’s dominant run to the title at the Winston-Salem Open last week.

Competing in his 17th consecutive Grand Slam main draw, Coric is enjoying his best result. It marks the first time he will appear in the second week of a major. The 21-year-old is up to a career-high No. 20 in the ATP Rankings and coming off his biggest victory to date, having upset Roger Federer in the Gerry Weber Open final in June.

On Sunday, Coric and Del Potro will meet for the first time.