It’s safe to say that all did not go according to plan this year at the US Open. 

The past two weeks in New York have seen plenty of shocking upsets that ranged from Monday morning casualties to the crowning of a new Grand Slam champion. USOpen.org takes a look back at the five most eyebrow-raising results this fortnight.

(20) Naomi Osaka d. (17) Serena Williams 6-2, 6-4, final

Even though Osaka had soundly beaten Williams in their only previous career meeting this year in Miami, the 20-year-old was playing in her first Grand Slam final (compared to 31 for Williams) and facing a crowd decidedly in favor of the American. Osaka was unfazed by the occasion, firing a huge first serve on championship point to seal the win.

She finished the day with 16 winners to 14 errors, earning $3.8 million for a brilliant two weeks of tennis. She’ll also make her debut in the Top 10 of the WTA rankings on Monday.

play video Highlights: John Millman vs. Roger Federer - Round 4

John Millman d. (2) Roger Federer 3-6, 7-5, 7-6, 7-6, Round of 16

Fans in Arthur Ashe Stadium could be forgiven for expecting this match to be a blowout. The 29-year-old Millman was appearing in the second week of a Grand Slam for the first time and had never beaten a Top-10 player. But while Federer was far from his best, committing 77 errors on the night, the Aussie battler showed incredible heart in saving set points in both the second and third sets, as well as rallying from 2-4 down in the fourth set.

“I was always of the opinion that I was in the fourth round for a reason,” said Millman. “I’ve never played anyone’s reputation... that’s the great thing about sport. There’s always upsets that can happen.”

Although he bowed out to Novak Djokovic in the next round, the last two weeks were a career highlight for Millman that earned him celebrity status in Australia.

play video Round 1 Highlights - Simona Halep vs Kaia Kanepi - Day1

Kaia Kanepi d. (1) Simona Halep 6-2, 6-4, Round 1

Kanepi came through qualifying to reach the US Open quarterfinals last year, but she had gone 9-12 in WTA main draw matches since then. Although Kanepi rekindled her old US Open magic and played a solid match, the first inside the new Louis Armstrong Stadium, it simply wasn’t Halep’s day. The World No. 1 arrived in New York on the back of an outstanding summer, but appeared frozen and only mustered nine winners in 18 games. She became the first top-seeded woman to lose in the first round of the US Open.

“I think players are playing more equally. There are not many players anymore who are leading the game,” said Kanepi. “Everybody can beat everybody on a good day, so that’s what I also thought.”

The Estonian proved her win wasn’t a fluke, going on to reach the fourth round before falling to Serena Williams in three sets.

play video Highlights: Lesia Tsurenko vs. Caroline Wozniacki - Round 2

Lesia Tsurenko d. (2) Caroline Wozniacki 6-4, 6-2, Round 2

Although a left knee injury had brought Wozniacki into this year’s US Open on a three-match losing streak, there was no way to expect the shocking performance she put in to lose to the World No. 36. Normally a backboard, she hit 35 errors to six winners and simply couldn’t get going in Louis Armstrong Stadium.

However, Tsurenko proved to be inspired by the biggest moment of her career. The Ukrainian rode the momentum all the way to her first Grand Slam quarterfinal.

play video AI Match Highlight: Muguruza vs. Muchova - Round 2

(Q) Karolina Muchova d. (12) Garbiñe Muguruza, 3-6, 6-3, 6-4, Round 2

The 22-year-old Czech player did well just to qualify for her first Grand Slam main draw, but wasn’t content to stop there. Ranked No. 202 and appearing on a show court at a big tournament for the first time, she quickly adjusted to her surroundings and played the match of her life. As the clock ticked past 1:00am in the new Louis Armstrong Stadium, she raised her arms in triumph after completing an unthinkable win over the two-time Grand Slam champion. 

Muchova lost in the third round to Ashleigh Barty, but will enter the Top 150 of the WTA rankings for the first time in her career on Monday.