NEW YORK – Another day, another surprising upset at the US Open.

Just 24 hours after Carlos Alcaraz suffered an early exit from the tournament, defending champion and No. 2 seed Novak Djokovic lost 6-4, 6-4, 2-6, 6-4 to No. 28 seed Alexei Popyrin in the third round on the same court.

When the 25-year-old Australian played in prime time at Arthur Ashe Stadium on Friday, few thought he had a chance against Djokovic, who had just won Olympic gold in Paris and was looking to make history with his 25th major title. The pair had already met twice at majors this season – at the Australian Open and at Wimbledon – and Popyrin failed to win either match.

But Friday was different.

Perhaps still riding the momentum of winning his first Masters 1000-level title at the Canadian Open earlier this month, and buoyed by his 50 winners that night and Djokovic’s weak serve, Popyrin played the best match of his career.

“It’s incredible because I’ve been to the third round about 15 times and never made it to the fourth,” Popyrin said on court after the match. “To do it against the greatest of all time is incredible. It’s a great feeling and all the hard work has paid off.”

Djokovic, who underwent knee surgery in June, later called his performance “terrible” and said it was “the worst tennis” he had ever played. The 37-year-old admitted he felt drained after an intense summer program that saw him experience several surface changes.

“I spent a lot of energy trying to win gold and when I came to New York I didn’t feel fresh mentally and physically,” Djokovic said. “But because it’s the US Open, I tried and did my best. I mean, I didn’t have any physical problems. I was just out of breath and you could see that in the way I played.”

Djokovic officially ended his Grand Slam season without a title for the first time since 2017. It is the first season since 2002 in which a member of the Big Three (Djokovic, Rafael Nadal and Roger Federer) has not won a major trophy.

And the tournament is now the only Grand Slam tournament in over 22 years in which the men’s number 2 or 3 did not reach the round of 16.

Needless to say, it’s been a surprising first week in Queens, and the men’s title is still up for grabs with two of the favourites now eliminated. So who has the best chance of lifting the trophy as we head into Day 6? Given how the tournament has started, predictions might be very difficult, but we’ll try anyway. (And yes, we know the players in the top half of the draw haven’t played their third round matches yet.)

Next up: Third round against Christopher O’Connell (Saturday)

The world number one was considered a favourite alongside Alcaraz and Djokovic before the tournament, but the announcement of his two positive tests for banned substances in March led to intense criticism and it was unclear how he would fare under the circumstances. Sinner, 23, lost the first set of his opening match against Mackenzie McDonald but otherwise comfortably advanced to the third round and his play has been largely unaffected by the off-court rumours.

Sinner has never made it past the quarterfinals in New York, but is the current Australian Open champion, having won the title in Cincinnati earlier this month in his last preliminary tournament. He is currently one of the best on hard court and can beat anyone else in the field.

Next up: Third round against No. 31 Flavio Cobolli (Saturday)

The 2021 winner is the only remaining US Open champion still in contention. He came into the tournament somewhat under the radar after lackluster results in Montreal and Cincinnati and without a title win all season. However, the crowd favorite dropped just one set en route to the third round and should defeat Cobolli in their first career meeting. Nuno Borges or Jakub Mensik would be waiting in the round of 16.

Medvedev, 28, would likely face Sinner in the quarterfinals, and it’s hard to imagine anyone having a better chance of beating the world number one than Medvedev. As a three-time US Open finalist, he certainly has experience on his side and thrives under the Ashe floodlights in front of a raucous crowd.

The winner of this presumed game would immediately become the favorite.

Next up: Fourth round against No. 28 Alexei Popyrin (Sunday)

As you’ve probably heard countless times, no American has won a major title since the 2003 US Open. But did you see what Tiafoe did in Friday’s third round against fellow countryman Ben Shelton? It took Tiafoe five sets and over four hours, but he pulled out all the stops and found an answer to Shelton’s powerful serve. At the end of the match, the 26-year-old became the first American since Andre Agassi (2001-2005) to reach the round of 16 of the tournament in five consecutive seasons.

Tiafoe is a stirring showman who thrives in front of the biggest crowds and on the biggest stages. He is a popular player in New York and will have the fans firmly behind him in every match he plays. He has made it clear that the US Open is his top priority – he even skipped this summer’s Olympics to best prepare for the surface. He made the final in Cincinnati and has reached the semifinals of the US Open in 2022. With Djokovic now out of the way, Tiafoe’s path to the quarterfinals – and beyond – has become significantly easier, and there is arguably no one who wants that more. When asked if an American could end the tournament’s drought, he called it “kind of a ‘why not?’ thing.” So why not Tiafoe?

Next up: Fourth round against No. 8 Casper Ruud (Sunday)

Let’s start with the obvious: Ruud, a 2022 US Open finalist, will not be an easy opponent and the match could well go either way. But like Tiafoe, Fritz will have the support of the home crowd and the added motivation of wanting to end a winless streak at majors – something he has previously said drives him.

And let’s not forget that he’s had an incredible season, putting in a strong performance in week one. He’s reached the round of 16 at every major this year — becoming the first American since Agassi to do so in a single season — and has won two titles in 2024, in addition to his Olympic bronze medal in doubles. Fritz, 26, hasn’t lost a set in three matches and had a particularly impressive second-round win over former Wimbledon finalist Matteo Berrettini. He’s reached four major quarterfinals in his career, including at the 2023 US Open, but has never advanced beyond the round. To quote Tiafoe, who Fritz could potentially play in the semifinals: “Why not?”

Next up: Fourth round against No. 9 Grigor Dimitrov (Sunday)

Several men were in contention for that final spot, including Popyrin, Ruud, Dimitrov and American Tommy Paul, but Rublev was ultimately chosen. After a somewhat confusing season, the 26-year-old finally seems to be back on track and has played top-notch tennis on the surface this summer, reaching the final in Montreal and the quarter-finals in Cincinnati and, despite some difficulties, finding ways to win in New York.

Despite winning his opening match and third round in straight sets, he fell two sets behind in the second round against Arthur Rinderknech. But Rublev fought back and battled his way to victory. It was only the second win of his career from 0-2 down and the first in nearly four years. Rublev, who has reached the quarterfinals of major tournaments 10 times, including four times at the US Open, has never managed to get past the last eight.

If he can beat a resurgent Dimitrov on Sunday, the winner of Tiafoe-Popyrin awaits. It’s likely that he will find a way to advance to the semifinals (or beyond) at some point, and perhaps he will recognise this as his best chance yet and seize the opportunity.