At three hours and 25 minutes, it was the longest best-of-three-set men's match of the year.
The Russian was asked afterwards if this was the biggest win of his career.
“For sure, No. 1 in the world,” he said. “You have to put 100%, 150% on the court to beat this guy.”
Djokovic had won their only previous meeting, ending Karatsev’s breakthrough run at the Australian Open in February with a 6-3, 6-4, 6-2 win in the semifinals. And it looked like it would be more of the same in the early stages of this match, as Djokovic grabbed an early break en route to a 3-0 lead.
But Karatsev struck back, winning seven of the next nine games to take the first set, 7-5, and after falling behind 2-0 in the second set, the Russian won four games in a row to build a 7-5, 4-2 lead.
Djokovic wasn’t finished by any means, though. He retaliated with four games in a row of his own to take the second set, 6-4, dusting it off with three straight winners—from Karatsev serving at 4-5, 40-30, Djokovic ripped a crosscourt backhand passing shot, a down-the-line backhand passing shot and a forehand winner up the line to clinch the second set and send the semifinal to a decider.
After six straight holds to start the third set, there was one final twist, and it went Karatsev’s way—he broke for 4-3 and held to make it 5-3, and though Djokovic fought off a match point in his next service game and held to close the gap to 5-4, the Russian held one last time to seal a marathon victory.
Perhaps the loudest statistic from the match was Karatsev saving 23 of 28 break points, and against arguably the greatest returner the sport has ever seen. He saved all 10 he faced in the third set.
“There’s not much that I can say was on my mind,” the Russian said about saving those 23 break points. “You have to play aggressive with these kinds of players. You’re playing against a wall—if you don’t play aggressive, it’s the same as just hitting against the wall. Everything comes back deep and he moves you a lot, and once you give him the opportunity to move you, you’re running a lot.
“I was trying to focus on playing aggressive, and that was the main goal.”
Despite the loss, Djokovic only had kind words for Karatsev in his post-match press conference.
“Well you never like losing at home, that’s for sure. It’s painful, it’s disappointing, and I don’t feel so great now,” he said. “But at the same time I have to congratulate Karatsev, who played very bravely. Whenever he needed to come up with his best shots, he did. Awesome performance from his side.
“My side, I played on quite a low level, in my opinion. Some flashes of good quality tennis, and I was fighting, I was really trying all the way. And the crowd was great—they carried me and tried to lift me up all the way to the end, and I think that it was because of them that I won the second set.
“In the third he was just the better player in the decisive moments. I had my chances, but that’s sport.”
Coming into 2021, the 27-year-old Karatsev had never even been to an ATP quarterfinal. He’s already done it three times this year—in addition to his Melbourne run, Karatsev won his first ATP title at the 500-level event in Dubai and now has a shot at adding a second piece of hardware in Belgrade.
Karatsev had also never beaten a player in the Top 40 before this year. He’s now beaten eight of them, including three Top 10 wins against Diego Schwartzman, Andrey Rublev and now No. 1 Djokovic.
The Russian will go for a fourth Top 10 win in the final as he takes on No. 10-ranked Matteo Berrettini, who beat Japan's Taro Daniel in his semifinal, 6-1, 6-7 (5), 6-0, after originally leading 6-1, 5-3.
Berrettini will be going for his fourth career ATP title, his first three all coming at ATP 250s as well—two on clay, at Gstaad in 2018 and Budapest in 2019, and one on grass at Stuttgart in 2019.
The Italian and the Russian will be playing each other for the first time.