Alexei Popyrin was emotionally overwhelmed after his stunning upset victory over Novak Djokovic at the US Open. As he won the final point, he loudly screamed excitement and relief, pumping his fist in the air.

Popyrin's reaction was understandable, given that he had never beaten Djokovic before and had lost to him twice in Grand Slam tournaments earlier this year. The Australian's win was a major upset, with Djokovic seeking to become the first player in tennis history with 25 Grand Slam singles titles.

Djokovic was gracious in defeat, admitting that he had played "some of the worst tennis" of his career and that Popyrin had deserved his victory. "Congratulations to him and his team," Djokovic said. "He definitely played better and deserved to win today."

2024 US Open - Day 5
NEW YORK, NEW YORK - AUGUST 30: Alexei Popyrin of Australia reacts after breaking serve against Novak Djokovic of Serbia during their Men's Singles Third Round match on Day Five of the 2024 US Open at USTA Billie Jean King National Tennis Center on August 30, 2024 in the Flushing neighborhood of the Queens borough of New York City. Photo by Sarah Stier/Getty Images

Popyrin's victory sets up a fourth-round encounter with American Frances Tiafoe, who reached the semi-finals in 2022 and the quarter-finals in 2023. The Australian will be looking to continue his giant-killing run and reach the quarter-finals of a Grand Slam tournament for the first time in his career.