Three upsets on Day 4 of the 2025 Australian Open

The fourth day of the 2025 Australian Open saw World No. 1 Jannik Sinner and No. 4 Taylor Fritz coast into the third round. On the women’s side, No. 2 Iga Swiatek and No. 4 Jasmine Paolini faced little resistance in their second-round matches. 

But the day wasn’t devoid of a few massive upsets.

Fifth-seeded Daniil Medvedev

The three-time Australian Open finalist ran into American teenager Learner Tien, who overcame a five-set marathon that went into a deep tiebreaker in the deciding set. Ultimately, the 19-year-old had more gas in the tank after four hours and 49 minutes amid a lively Melbourne crowd. The tiebreaker ended in an anti-climatic fashion as Medvedev made back-to-back unforced errors to give Lien the 10-7 win. The Russian had jumped out to a 6-4 lead before Tien showed tremendous poise to draw level with a few returning winners. Tien has been on a roll recently, reaching the finals of the Next Gen ATP Finals and making deep runs in Challenger events. He will next face Frenchman Corentin Moutet in the third round. As for Medvedev, the result marks a disappointing start to the year after he reached the finals at two majors last year — Wimbledon and Australian Open.

17th-seeded Frances Tiafoe

A fan-favorite in Melbourne for years, Tiafoe had the crowd behind him against unseeded Hungarian Fabian Marozsan. But the crowd support didn’t seem to matter as Marozsan had an answer for everything Tiafoe dished at him. Even as the American went up two sets to one, it never felt like Marozsan was out of the contest as he kept firing laser winners from all angles. The Hungarian had a final 63-48 advantage on winners and a whopping 7-1 on return winners. He used Tiafoe’s quick serve to his benefit with his baseline-oriented skills. Marozsan will next face veteran Italian Lorenzo Sonego in the third round. Tiafoe needs to try and regroup after a series of poor results since his semifinal finish at last year’s U.S. Open.

18th-seeded Hubert Hurkacz

After reaching the quarterfinal at last year’s Australian Open, Hurkacz has now suffered early exits in four consecutive majors. In a stunning outcome, he crashed out in straight sets, 6-4, 6-4, 6-2, to unseeded Serbian Miomir Kecmanovic in the second round. It was a rather shocking outcome since the Pole was fresh off a finals appearance at the United Cup with his country and was tipped as one of the dark horses to make a deep run in Melbourne. Furthermore, he recently added the legendary Ivan Lendl to his coaching team. It has to be a tough pill for the Pole and his team. For Kecmanovic, it’s the biggest win of his career since he reached the fourth round of the 2022 Australian Open.

So, who’s on upset alert on Day 5?  No. 3 Carlos Alcaraz can’t take Nuno Borges lightly given the latter’s recent form. On the women’s side, No. 7 Jessica Pegula will be pushed to her limit by rising Serb Olga Danilovic. (We predicted
Medvedev’s upset by Lien).