No man has ever won more than five U.S. Open tennis championships, which is a much lower career total than tennis greats have recorded at the other Grand Slam events. Does this mean the U.S. Open is an upset-friendly tournament? If so, is that also true on the women’s side?

Underdog players at the 2023 U.S. Open will look to take advantage of what appears to be a pretty open field on both the men’s and, particularly, the women’s side. Outside of Novak Djokovic and Carlos Alcaraz, it seems as if all the other highly-ranked men at this tournament should be concerned about upsets based on their inconsistent performances.

With that in mind, let’s review some of the most famous upsets ever witnessed at the U.S. Open.

Ranking the Top 10 Biggest Upsets in U.S. Open Tennis History

  1. 2022 Women’s Second Round: Serena Williams defeats No. 2 Anett Kontaveit

Closing Betting Line: Williams +190
Match Result: 7-6 (7-4), 2-6, 6-2 

We’ll start this top 10 list with a pair of 2022 U.S. Open upsets.

It’s hard to think of Serena Williams going into a match an underdog, but that’s what she was heading into the second round of her final Grand Slam event. In 2022, a 40-year-old Williams eliminated No. 2 seed Anett Kontaveit in a thrilling three-set matchup. With her victory, Williams became the oldest player in WTA history to beat one of a tournament’s top three seeds.

Williams would fall in the next round, and the Estonian Kontaveit is still looking for her first career trip to a Grand Slam semifinal. Expect to see Serena again on this list, although on the other side of a match’s outcome. 

  1. 2022 Men’s Round of 16: No. 22 Frances Tiafoe defeats No. 2 Rafael Nadal

Closing Betting Line: Tiafoe +400
Match Result: 6-4, 4-6, 6-4, 6-3 

On the men’s side of the 2022 U.S. Open tennis tournament, there was a showdown that might be remembered as tennis legend Rafael Nadal’s last-ever competitive Grand Slam match. On paper, at least, this wasn’t as great an upset as some of the other entries on this top 10 list, but Tiafoe’s dismissal of Nadal sent shockwaves throughout the tennis world.

Even LeBron James tweeted about this one, as the young American Tiafoe finally got a signature win and marched into his first career Grand Slam semifinal, where he gave eventual winner Carlos Alcaraz a run for his money. Meanwhile, Nadal has only competed in one Grand Slam since, and who knows if we’ll ever see the king of clay again as he battles injuries and an overall decline in his play.

  1. 2005 Women’s First Round: Ekaterina Bychkova defeats No. 5 Svetlana Kuznetsova

Match Result: 6-3, 6-2

Everything had come up roses for ninth-seeded Svetlana Kuznetsova at the 2004 U.S. Open, where she defeated fellow Russian and No. 6 seed Elena Dementieva in straight sets to claim the title. Those two players were among a group of Russians who had held a staggering five of the top 10 seeds at the 2004 U.S. Open.

The following year, Kuznetsova, then seeded fifth, would lose to an unseeded Russian, Ekaterina Bychkova, in straight sets in the 2005 U.S. Open’s first round. The stunning loss made Kuznetsova the first reigning champion in U.S. Open history to fall in the first round.  

  1. 2000 Men’s Second Round: Arnaud Clement defeats No. 1 Andre Agassi

Match Result: 6-3, 6-2, 6-4

Like Svetlana Kuznetsova in 2005, Andre Agassi was another defending U.S. Open champion who fell early in the following year’s tournament.

In 1999, Agassi, the world’s No. 1-ranked player, held off fellow American Todd Martin, the No. 7 seed, in five sets to claim his second U.S. Open championship. In 2000, Agassi cruised past American wild card Alex Kim in straight sets before a matchup with Arnaud Clement, an unseeded 22-year-old from France. Clement had come within two points of defeating Agassi at the 1999 French Open, so there was already some history between the two.

In a real shocker, Clement put away Agassi in straight sets.

“I don’t know what to tell you. ... You’ve got to give credit where credit’s due. Spend your energy writing about the way he played,” a defeated Agassi told reporters.

  1. 2017 Women’s Semifinals: Sloane Stephens defeats No. 9 Venus Williams

Match Result: 6-1, 0-6, 7-5

This wasn’t just an upset, it was part of Sloane Stephens’ breakthrough 2017 U.S. Open run. Prior to the 2017 event, the talented American had yet to turn her teenage stardom into noteworthy success. Although she was still only 24, she had already competed in five U.S. Opens, failing to reach to quarterfinals every time.

2017 would prove to be a different story, as the unseeded Stephens knocked off No. 11 seed Dominika Cibulkova in the second round, No. 30 seed Julia Gorges in the Round of 16, and No. 16 seed Anastasija Sevastova in the quarterfinals before her semifinal matchup with No. 9 Venus Williams. A late break sealed Stephens’ victory over Williams in the third set.

“I have no words to describe what I’m feeling,” a triumphant Stephens said.

Stephens went on to beat fellow American Madison Keys and claim the title a few days later.

  1. 2009 Men’s Final: No. 6 Juan Martin del Potro defeats No. 1 Roger Federer

Match Result: 3-6, 7-6 (7-5), 4-6, 7-6 (7-4), 6-2

Roger Federer, the world’s No. 1-ranked player, was on quite a hot streak heading into the 2009 U.S. Open. He had won both the 2009 French Open and Wimbledon titles, the first of which had given him an elusive career Grand Slam.

Federer was also a five-time defending U.S. Open champion (and, no, that isn’t a typo) when he arrived at the 2009 tournament. He was hoping to become the first man since Bill Tilden in the 1920s to win six straight titles at Flushing.

Federer finally fell in a five-set thriller that saw Argentina’s Juan Martin del Potro win two tiebreaks. Federer would never win another U.S. Open after that loss.

  1. 2015 Women’s Semifinals: Roberta Vinci defeats No. 1 Serena Williams

Closing Betting Line: Vinci +3000
Match result: 2-6, 6-4, 6-4

Earlier in this list, we warned readers that Serena Williams would appear on the losing side of one of these top 10 U.S. Open upsets, so here it is.

Much like Roger Federer in 2009, the American star Williams was on a roll entering the 2015 U.S. Open. A three-time defending champion, Serena came into the semifinals having just defeated her sister, Venus, in a grueling three-set quarterfinal. She drew unseeded Italian Roberta Vinci as her semifinal opponent. Vinci had not yet faced a seeded player in the tournament.

Despite winning the first set, Williams’ 26-match Grand Slam winning streak would come to a halt against Vinci.

“I made more unforced errors than I normally would make, but I think she (Vinci) just played really well. She did not want to lose today. Neither did I, incidentally. But she really didn’t, either,” said the defeated American.

Vinci would go on to lose to Flavia Pennetta in the final.

  1. 2008 Women’s Second Round: Julie Coin defeats No. 1 Ana Ivanovic

Match Result: 6-3, 4-6, 6-3

2008 French Open champion Ana Ivanovic had climbed the tennis mountain to become the No. 1-ranked player in the world. Her opponent in the second round of the 2008 U.S. Open was No. 188-ranked qualifier Julie Coin of France, who was competing in her first Grand Slam event.

A few hours after the match began, Ivanovic was heading home.

“I don’t realize yet that I beat the number one in the world. I don’t realize that I played at the big court. I don’t know how I’m going sleep tonight,” Coin said after becoming one of the lowest-ever ranked players to defeat a world No. 1. 

  1. 1986 Men’s First Round: Paul Annacone defeats No. 9 John McEnroe

Match Result: 1-6, 6-1, 6-3, 6-3

An injury-riddled 1986 season had jeopardized John McEnroe’s image as the face of tennis. McEnroe had reached both the 1984 and 1985 U.S. Open finals, winning the former. However, the 1986 U.S. Open was his first and only Grand Slam event that year, and he was eager to move up from his No. 9 ranking.

This is how The New York Times described McEnroe’s performance against unseeded Paul Annacone: “The McEnroe trademarks -- curly hair, pained expression and even some of that famous touch at the net -- were on display yesterday, but in the end, it was as if someone had sneaked on the Stadium Court and masqueraded as the former No. 1 player in the world.”

Perhaps his 1986 first-round loss was a sign of things to come. Only 27 at the time, McEnroe never reached another Grand Slam men’s singles final. Nevertheless, among all U.S. Open tennis players, “Johnny Mac” is still iconic.

  1. 1990 Men’s First Round: Alexander Volkov defeats No. 1 Stefan Edberg

Match Result: 6-3, 7-6 (7-3), 6-2

Swedish former world No. 1 Stefan Edberg won both the 1991 and 1992 U.S. Open titles. However, before he reached the level of champion, he failed to win a single set against the Soviet Union’s Alexander Volkov in the first round at Flushing in 1990.

“This is something you need to sit and think about," Edberg said after losing to Volkov. "At the moment, I can't tell you too many reasons because I don't know myself. You just think it over and try to figure it out so it doesn't happen again."

Given what Edberg was about to do over the next two years, this first-round loss was the biggest upset in U.S. Open tennis history.

Parameters of Rankings

These match rankings were based on the difference in the players’ seedings, the perceived difference in the players’ talent, the match’s cultural impact, and some personal preferences on the part of the individual compiling the list.

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