Twenty-seven down, one to go.

With a five-set win over Alexander Zverev of Germany on Friday night, Novak Djokovic moved to within a single match victory of pulling off the most hallowed achievement in tennis.

After winning the Australian Open, the French Open and Wimbledon this year and knocking out his first challengers at the US Open, Djokovic now has to defeat only Daniil Medvedev of Russia in Sunday’s final to become the first man to win the Grand Slam in a calendar year in 52 years.

And he got there in style, coming from behind early on, then surviving an onslaught from an opponent who seemed for a time that he might just have Djokovic’s number.

Zverev came close, forcing Djokovic to go the distance in a gruelling 4-6, 6-2, 6-4, 4-6, 6-2 win, but the razor-thin margin only made Djokovic’s number at the grand slams in 2021 seem more mysterious.

On Sunday, when Djokovic takes on Medvedev, he will play for history. He is tied with his biggest rivals, Roger Federer and Rafael Nadal, in the race for the most career grand slam titles with 20, a competition that Djokovic is determined to win so he can cement his legacy as the greatest player ever. It is the thing that would make Djokovic the biggest of the Big Three forever.

“The job is not done,” Djokovic said just past midnight on Saturday morning. “The excitement is there. The motivation is there, without a doubt. Probably more than ever. But I have one more to go.”

When the draw for the US Open came out two weeks ago, a match with Zverev in the semi-final round loomed as one of the biggest potential obstacles for Djokovic in his hunt for his sport’s holy grail. Zverev, 24, stands 6 feet 6 inches tall, floats around the tennis court with the grace of an NBA shooting guard, and can unleash 130mph serves and rocketing forehands at will when he is playing well.

The match started as so many others have for Djokovic — with an early hiccup that made the mountain he would have to climb that much steeper. This slip occurred as Djokovic served with the score tied at four games each.

Zverev inched ahead, and then Djokovic double-faulted to give the big German a chance to serve out the set. He did not waste it. Zverev won the opening set, just as Djokovic’s previous three opponents had.

But Djokovic is as good at flipping the script as anyone who has ever picked up a racket.

Just as he had in his last three matches, Djokovic raised the level of his game and surged to a second-set lead. An hour-and-a-quarter after they began, Djokovic and Zverev were back where they started, all tied up.

The turning point of the match came nearly an hour later. With Zverev serving to stay in the set, Djokovic put on a display of tennis genius.

No one in Arthur Ashe Stadium knew better than Zverev that rallying with Djokovic would result in a slow and painful death. And yet, somehow, Djokovic managed to play a kind of tennis Tai chi, sustaining rallies of 18, 32 and 12 shots to get to triple set point. Zverev survived rallies of 21 shots and an absurd 53 to save the first two.

Then, on the 15th shot of the sixth point of the game, he could do no better than float a desperate lob to Djokovic, who was waiting at the net to swat it down to take the lead for the first time all night.

Zverev would not go quietly, though. With Djokovic serving at 1-1, Zverev battled to turn the third game into a mini-marathon, digging in and clinching it with a slick forehand passing shot that Djokovic could not come close to touching. With Zverev’s serve cranking up beyond the 130mph mark, Djokovic could not find the opening to get even. Djokovic’s chance at history was down to a single set.

Holding a 1-0 lead in the fifth set, Djokovic — and likely everyone else in the stadium — could sense Zverev growing shaky. A double-fault gave Djokovic a sniff at a break at 15-30. A backhand error gave Djokovic the break point. Then one more rally went the wrong way for Zverev, and the set became a seemingly inevitable series of Zverev misses, including one leaping overhead smashed wildly out of bounds.

One last backhand error for one last service break and after 3 hours and 35 minutes, Zverev was finally done.

A match that could have gone either way, Zverev called it. “It went his way,” he said. “Very often it does.”

And now the grand slam math becomes very, very simple: The only numbers that mattered were these — 27 matches down, one to go.

New York Times News Service