US Open 2025: 5 upset alerts on Day 4 ft. Jessica Pegula, Emma Navarro

The 2025 US Open is hosting some of the best players in the world this week. The first two days of the final Grand Slam of the year have produced plenty of scintillating action.

Novak Djokovic and Carlos Alcaraz have started their campaigns on a positive note. They will be eager to build momentum and improve further in the next few rounds.

Meanwhile, Iga Swiatek and Aryna Sabalenka also made no mistakes during their early tests in New York. The Pole has been in excellent form and is one of the favorites to win this year.

With exciting matches lined up on Day Four, let's analyze some where we could see a possible upset.

5) Jelena Ostapenko

First up is Jelena Ostapenko.

Ostapenko has had a hot and cold season this year. After a runner-up finish in Doha, she captured the crown in Stuttgart. She also reached the fourth round of the Italian Open, but lost to Jasmine Paolini in straight sets.

The Latvian arrived in New York after a third round exit in Cincinnati. She made a solid start to her campaign by defeating Wang Xin Yu, 6-4, 6-3.

Ostapenko is expected to do well in the second round but faces Montreal quarterfinalist Taylor Townsend. The in-form American started on a strong note against Antonia Ruzic and will be tough to beat on Wednesday (August 27).

4) Belinda Bencic

Bencic at the 2025 US Open - Day 1 - Source: Getty

Second on the list is Belinda Bencic.

Bencic has taken very little time to find her rhythm after her maternity break on tour. She's already won a hard court title in Abu Dhabi and will be eager to do well in New York. The Swiss pro eliminated Zhang Shuai in the first round, 6-3, 6-3.

Bencic will take on local favorite Ann Li on Wednesday. The American has secured runner-up finishes in Singapore and Cleveland this year and looks in fine form in New York. She chalked up a resilient win against Rebecca Sramkova in the first round, 4-6, 6-2, 6-4.

Considering Bencic's shaky form in the last few weeks, Li could create problems for the Swiss star in the second round.

3) Holger Rune

Rune at the 2025 US Open - Day 2 - Source: Getty

Third on the list is Holger Rune.

Rune is one of the most talented youngsters on tour. He not only clinched the title in Barcelona, but also secured a runner-up finish in Indian Wells this year. The Dane started his US Open campaign with a hard-fought victory over Botic Van De Zandschulp, 6-3, 7-6(4), 7-6(2).

The Dane will take on big serving Jan-Lennard Struff in the next round. He lost the previous encounter against the German in straight sets last year (Munich). Despite Rune's recent quarterfinal run in Cincinnati, Struff's dependable record at the Majors will make this an interesting bout.

2) Jessica Pegula

Pegula at the 2025 US Open - Day 1 - Source: Getty

Second on the list is Jessica Pegula.

Pegula was one win away from capturing the US Open last year. She's had a solid season so far, amassing title-winning runs in Austin, Charleston and Bad Homburg (on grass). The American arrived in New York on the back of disappointing third-round exits in Montreal and Cincinnati. She steadied the ship in the first round by cruising past Mayar Sherif, 6-0, 6-4.

Pegula will face Anna Blinkova in the second round. She leads the head-to-head against the Russian, but lost to her in Indian Wells last year. Blinkova has also pushed her to three sets a couple of times in their last five encounters. Considering their current form, a close contest will be on the cards.

1) Emma Navarro

Last on the list is Emma Navarro.

Apart from a title-winning run in Merida, she also reached the fourth round of the Wimbledon Championships this year.

More recently, the American endured early exits in Montreal, Cincinnati and Monterrey. She instantly made amends by defeating Yafan Wang in the first round, 7-6(9), 6-3.

Navarro will now take on Caty McNally on Wednesday. The youngster has secured two ITF titles this year and also reached the third round in Montreal. Considering her confident straight sets win over Jil Teichmann in the first round, she could give Navarro a run for her money at the US Open.