In this closing moment, against Daniil Medvedev, Sebastian Korda crosses the finish line

MATCH POINT: Korda gets it done against the former No. 1

Sebastian Korda has been tantalizingly close to a couple of career-changing breakthrough wins. So close that he was probably rehearsing his victory celebrations in his mind.

At Indian Wells last year, he led his childhood hero Rafael Nadal 5-2 in the third set, before falling in a tiebreaker. Two weeks ago in Adelaide, he reached match point against Novak Djokovic, before giving that one back, too. Both times, Korda was the superior player, right up until the moment his victory seemed assured. Then he struggled to put a ball in the court.

The 22-year-old Floridian, and son of 1998 Australian Open winner Petr Korda, is one of the game’s smoothest ball-strikers. But in those closing moments, it almost seemed as if his flawlessness worked against him. Any hint of extra tension in his arm was enough to cause a tiny—or perhaps not so tiny—glitch in his finely-tuned stroke production, which in turn was enough to produce an error.

To combat those moments of doubt, and the pessimism that can grow from them, Korda says he came to Australia with a new mindset: He’s not going to let himself have a single less-than-upbeat thought. Anywhere. Anytime. Ever. Not even at lunch.

“I just kind of really, really worked hard on just zero negative thoughts,” Korda says, who adds that new coach Radek Stepanek is a big believer in the power of positivity. “Throughout this whole year, I haven’t had one negative thought, whether it’s waiting for transportation to go to the courts, whether it’s eating lunch, whether it’s doing anything.

“That’s one of the biggest things is kind of just having a new motto of, like, positive energy is more positive than negative energy.”

Korda’s opponent on Friday in Melbourne, Daniil Medvedev, is not an immortal like Nadal or Djokovic. But he is a Grand Slam champion, a former No. 1, and a perennial Top 10 player. For the 31st-ranked Korda, a win over the Russian might not qualify as career-changing, but it would certainly be career-affirming. Not surprisingly, Korda started well and struggled late. He needed every positive thought he could muster.

Korda started so well in the first set that he found himself up two quick breaks. He took advantage of Medvedev’s deep court positioning and anticipated his crosscourt rally pattern. Then Medvedev dug in and improved his depth, and Korda gave both breaks back.

The same thing happened in the first-set tiebreaker. When the score was tied, Korda’s attack was assured: He hit a big forehand at 4-4, moved forward at 5-5, threaded a perfect topspin lob at 6-6; hit a forehand winner at 7-7. But every time he went ahead, that self-assurance vanished: At 5-4, he double faulted; at 6-5, he netted a backhand; at 7-6, he sent a backhand long.

His strokes had gone glitchy again. Were we going to see a rerun of his Nadal and Djokovic collapses?

Finally, at 8-7—his fourth set point—Korda put a service return on the baseline, and Medvedev couldn’t handle it. Korda was probably helped by the fact that he didn’t have to think about that shot, and his arm didn’t have time to get tense.

The pattern held again in the third set. Korda went up a break, and was two games from the victory when he walked out to serve at 4-3. Then he started missing. He missed an easy volley long, and put a backhand into the net at break point. His strokes had gone glitchy again. Were we going to see a rerun of his Nadal and Djokovic collapses?

This is where his reserves of positive energy must have helped. Korda put that break behind him and held twice to reach a tiebreaker. There he came out firing, and built a winner-fueled 6-1 lead. Five match points, what could go wrong?

Throughout this whole year, I haven’t had one negative thought, whether it’s waiting for transportation to go to the courts, whether it’s eating lunch, whether it’s doing anything. Sebastian Korda

Well…at 6-2, he hit a forehand long; at 6-3, he hit a backhand into the net; at 6-4, he had his last chance to win the match on his serve. He and Medvedev rallied. Korda just got his arm through a couple of nervous backhands. Finally, he let loose with a down the line forehand that looked for half a second as if it would fly wide. But it didn’t. He had just enough topspin on it to bring it down. Upset—7-6 (7), 6-3, 7-6 (4)—complete.

“Probably one of the better matches I’ve played in my career,” Korda said. “Just stuck with the game plan, kept going after it. I think positive mentally throughout it. No matter what happened, kept pushing forward. I think that was the biggest thing that I did today.

“Losing my serve after being 40-15 up, you know, it’s OK, next point. Don’t worry, keep going, do your thing.”

If Korda can keep doing his thing—i.e., keep the tension out of his arm and the smooth swings coming—there will be many more breakthroughs to come.