Alexei Popyrin upset Djokovic at the US Open 3rd round, ending his chance for the 25th Grand Slam.
In Paris, Djokovic fought for gold at the Olympics but seemed tired against a motivated Australian, who achieved a major win.
Djokovic stated to reporters that he had exerted considerable energy in securing the gold and arrived in New York without feeling mentally or physically rejuvenated.
Despite feeling tired, I still gave my best during the US Open without any physical issues. It was evident from my performance.
Popyrin, who fell short of Djokovic at the Australian Open and Wimbledon this year, threw up his arms in celebration and grinned broadly after defeating the current champion to make it to a major semifinal for the first time.
Popyrin said, "Third time lucky" in court.
During Wimbledon and the Australian Open, conflicts were apparent. Although I had several opportunities, I failed to capitalize on them. However, in this particular encounter, I played exceptionally well and effectively seized my opportunities.
In the opening set, Djokovic faced five breakpoint opportunities, but was unable to convert any of them. Popyrin, on the other hand, broke serve on his first opportunity to take a 5-4 lead and win the first set.
After Djokovic's volley went wide in the second set, granting Popyrin a 3-2 lead, Popyrin managed to break again and secure the second set by skillfully executing a serve and volley, ultimately gaining control of the match.
In the third set, Djokovic created an opportunity to stage a comeback. He gained an advantage by breaking Popyrin's service with a forehand shot that proved too challenging for him to handle. As a result, Djokovic claimed the set, leading to a rematch being mandated.
The upset attempt, however, was short-lived as Popyrin gave a thunderous shout in the fourth game as he smashed a fierce forehand winner to break the serve and take a 3-2 lead. On match point, he sealed the shock as Djokovic's forehand went long.
In the Grand Slam match, Djokovic demonstrated a notable number of double faults, tallying up to 14, setting a new personal record. Meanwhile, his 25-year-old opponent showcased an impressive display, securing 50 wins.
Djokovic stated that playing on a quick surface without a strong serve, a low first-serve percentage, and many double faults made it impossible to win. He also described the match as an awful experience for him.
Novak Djokovic's recent loss marks the first time since 2017 that he will conclude the season without securing a Grand Slam victory.
Carlos Alcaraz, third seed and favorite in the tournament, was shocked by Botic van de Zandschulp in straight sets the night before the big match at Arthur Ashe Stadium.
Popyrin is scheduled to face American Frances Tiafoe in the fourth round.