On Thursday, the top seeds in the men's and women's draw, Jannik Sinner and Iga Swiatek, rolled on to the third round.

In the women's draw, No. 4 seed Elena Rybakina unexpectedly withdrew hours before her second-round match due to injury, while two-time U.S. Open champion Naomi Osaka narrowly fell to Karolina Muchova in straight sets.

But the biggest story of the day was Arthur Ashe's night session, where Botic van de Zandschulp—who contemplated retirement as recently as May—stunned Carlos Alcaraz.

After winning the 2024 French Open, Alcaraz became the youngest player to win a Grand Slam on all three surfaces. He was the favorite to win the U.S. Open and had won 15 straight Grand Slam matches.

With the Spaniard eliminated, the top half of the draw is now wide open.

Here are the top reactions from Thursday's action.

Thursday U.S. Open Results

Men's Singles

No. 1 Jannik Sinner def. Alex Michelsen, 6-4, 6-0, 6-2

Botic Van de Zandschulp def. No. 3 Carlos Alcaraz, 6-1, 7-5, 6-4

No. 5 Daniil Medvedev def. Fabian Marozsan, 6-3, 6-2, 7-6(5)

Jordan Thompson def. No. 7 Hubert Hurkacz, 7-6(2), 6-1, 7-5

No. 10 Alex de Minaur def. Otto Virtanen, 7-5, 6-1, 7-6(3)

No. 14 Tommy Paul def. Max Purcell, 7-5, 6-0, 1-0 (retired)

Tomas Machac def. No. 16 Sebastian Korda, 6-2, 6-4, 6-4

Gabriel Diallo def. No. 24 Arthur Fils, 7-5, 6-7(3), 6-4, 6-4

No. 25 Jack Draper def. Facundo Diaz Acosta, 6-4, 6-2, 6-2

No. 30 Matteo Arnaldi def. Roman Safiullin, 6-2, 6-4, 6-4

No. 31 Flavio Cobolli def. Zizou Bergs, 4-6, 6-3, 7-5, 6-3

Women's Singles

No. 1 Iga Swiatek def. Ena Shibahara, 6-0, 6-1

Jessica Ponchet def. No. 4 Elena Rybakina (Walkover)

No. 5 Jasmine Paolni def. Karolina Pliskova, 0-0 (retired)

No. 6 Jessica Pegula def. Sofia Kenin, 7-6(4), 6-3

No. 15 Anna Kalinskaya def. Anna Bondar, 6-2, 6-4

No. 16 Liudmila Samsonova def. Marie Bouzkova, 3-6, 7-6(1), 6-3

No. 18 Diana Shnaider def. Clara Tauson, 6-4, 6-4

Ashlyn Krueger def. No. 21 Mirra Andreeva, 6-1, 6-4

No. 22 Beatriz Hadda Maia def. Sara Sorribes Tormo, 6-2, 6-1

No. 25 Anastasia Pavlyuchenkova def. Elisabetta Cocciaretto, 5-7, 6-1, 6-2

No. 30 Yulia Putintseva def. Xinyu Wang, 6-1, 7-6(4)

Jessica Bouzas Maneiro def. No. 31 Katie Boulter, 7-5, 7-5

Carlos Alcaraz Stunned in Second Round

Carlos Alcaraz has fallen.

The 21-year-old, who was considered the favorite to win the U.S. Open after winning the last two Grand Slams, fell to Botic Van de Zandschulp, Thursday on Arthur Ashe.

The four-time Grand Slam champion struggled to find consistency throughout the entire match, notably on the Dutchman's first serve.

Van de Zandschulp won 79% of points on his first serve, committing just 21 unforced errors.

In the Spaniard's absence, there is a significant void in the top half of the men's draw, one that Jannik Sinner will look to capitalize on.

Meanwhile, Van de Zandschulp, who in 2021 became the third qualifier in the Open Era to reach the quarterfinal round of the U.S. Open, will face Jack Draper in the third round.

Jannik Sinner Dominant in Victory

For the second consecutive match, No. 1 seed Jannik Sinner got off to a slow start.

The top-seeded Italian won the first set over 20-year-old American Alex Michelsen, 6-4, despite committing 13 unforced errors and winning just 25% of points behind his second serve.

For the second straight match, though, the first set proved to be an anomaly.

In fact, Sinner played a dominant second set, winning 6-0 in just 27 minutes, followed by a third set in which he won every single point on his first serve.

The world No. 1 committed three more errors in the first set than the last two sets combined.

Sinner has managed to escape matches despite early struggles; however, as the draw tightens, he'll likely need improved consistency from the get-go to avoid burying himself into too deep of a hole.

The 23-year-old is still among the three favorites to win the U.S. Open and should not face any real challenges until he faces Tommy Paul, whom he could potentially meet in the fourth round.

Iga Swiatek Finds Top Form, Elena Rybakina Forced to Withdraw

After struggling through the entirety of her first-round match and squashing all three of her opponent's second-set point opportunities, No. 1 seed Iga Swiatek bounced back in resounding fashion.

The former U.S. Open champion faced few challenges against world No. 217 Ena Shibahara, defeating the 26-year-old in just 65 minutes while dropping just one total game.

The biggest difference in Swiatek's second-round match was her consistency.

The 23-year-old committed just six unforced errors, compared to the 41 she hit in her first round match against Kamilla Rakhimova.

Furthermore, she was able to establish rhythm early on her serve.

While Swiatek was able to dominate, the withdrawal of No. 4 seed Elena Rybakina just hours before her second-round match sent shockwaves through the women's draw.

Rybakina possessed the fourth-best odds to win the U.S. Open, according to Draftkings Sportsbook.

Additionally, the 25-year-old is just one of few to have a successful record against Swiatek, holding a 4-2 record in their six head-to-head matchups.

Mirra Andreeva Suffers Stunning Upset

After losing the first set of her opening round match to Shuai Zhang 6-0, it was imperative that Ashlyn Krueger got off to a quick start, especially against teenage phenom Mirra Andreeva.

And that's exactly what the 20-year-old American did.

Krueger dominated the first set, winning 6-1 in just 20 minutes.

Her serve made the difference early, as she won 13 of 15 points on her first serve in the opening set, while she committed just four unforced errors.

In the second set, she immediately broke Andreeva's serve with a beautiful crosscourt backhand, followed by a well-placed volley.

The two continued to break each other's serves game after game, but in the end, it was Krueger's consistent yet powerful strokes that were too much for the No. 21 seed to overcome.

While Andreeva was considered a dark horse contender in this year's tournament, Krueger is instead moving on with a legitimate chance of reaching the fourth round.