The US Open always brings drama to the hard courts of New York, but few expected the Round of 16 to feature such a remarkable underdog story. On Monday, September 1, 2025, Swiss qualifier Leandro Riedi, ranked No. 435 in the world, steps onto the court to face Australia’s Alex de Minaur, the tournament’s eighth seed and a staple of the sport’s elite. The matchup is set for 11:00 AM ET at the USTA Billie Jean King National Tennis Center, and tennis fans everywhere are buzzing about the clash of a surging longshot and a proven Grand Slam performer.
Riedi’s journey to the second week of a major has been nothing short of extraordinary. Using a protected ranking after an injury setback, he fought through three rounds of qualifying just to reach the US Open main draw. Once there, he wasted no time making headlines. In his first-round match, Riedi dispatched Pedro Martínez in straight sets, 6-4, 6-2, 6-3, showing off sharp serve placement and a newfound aggression from the baseline. If that performance turned a few heads, his second-round heroics sent shockwaves through the tennis world. Down two sets to the 19th seed Francisco Cerúndolo, Riedi mounted a gutsy comeback, prevailing 3-6, 4-6, 6-4, 6-4, 6-2. The Swiss player’s resilience and five-set stamina were on full display, earning him a reputation as the tournament’s comeback king.
Riedi’s third-round test was cut short when his opponent, Kamil Majchrzak, retired at 5-3 in the opening set, allowing Riedi to conserve energy for his biggest challenge yet. Entering the tournament as the world No. 435—his career best was No. 117 just a year prior—Riedi’s run marks the greatest ranking differential in this year’s US Open. He’s now 11-2 in matches this season, with a 23-9 record in sets played and an eye-popping 8.6 aces per match, according to the latest stats. On hard courts over the past year, he’s gone 8-1, winning 85.3% of his service games and 29.7% of his return games, and converting 32.5% of his break points. His momentum is undeniable, but he faces a mountain in the form of Alex de Minaur.
De Minaur, meanwhile, has been a model of consistency and excellence. The Australian world No. 8 is known for his relentless court coverage, explosive pace, and tactical discipline. This is his 13th appearance in a Grand Slam fourth round and his fifth at the US Open, as he aims for a sixth career quarterfinal and a third in New York. De Minaur’s 2025 hard court campaign has been impressive: he owns a 35-15 match record with one tournament win on the surface, and his service and return games are among the most efficient on tour. He’s won 79.5% of his service games and 29.6% of his return games on hard courts over the past 12 months, and his 46% break point conversion rate leads all players in that span.
At this year’s US Open, de Minaur has dropped only one set. He opened his campaign with a confident 6-3, 6-4, 6-4 win over Christopher O’Connell, followed by a 6-2, 6-4, 6-2 rout of Shintaro Mochizuki. In the third round, he was leading Daniel Altmaier when the German retired, trailing 6-7(9), 6-3, 6-4, 2-0. De Minaur’s form is peaking at just the right time, and his defensive prowess makes him a nightmare for any opponent—especially one playing the biggest match of his career.
Oddsmakers have taken notice. De Minaur is a heavy favorite, with odds of -1587 to win compared to Riedi’s +775 (some books even list Riedi at +1000). The implied probability from several predictive models gives de Minaur a 91% chance to advance, with an 83% chance of taking the first set. Even so, Riedi’s recent five-set heroics and qualifying momentum mean he can’t be counted out entirely. Some experts suggest he could snatch a set, especially if his serve is firing and he channels the fearless aggression that’s defined his run so far.
There’s no prior head-to-head history between these two, adding another layer of intrigue to the matchup. De Minaur’s experience at this stage is undeniable, but Riedi’s storybook run has captured the imagination of fans and pundits alike. As one analysis put it, “Riedi’s week has featured greater durability, sharper serve placement and more aggressive striking from the baseline. Those traits, combined with the momentum of back-to-back wins from qualifying all the way to the fourth round, enhance his threat as a longshot on the New York hardcourts.”
The stakes couldn’t be higher. A win for Riedi would be one of the most improbable quarterfinal runs in recent US Open memory, while a victory for de Minaur would further cement his place among the game’s elite and set up a tantalizing showdown with the winner of the Andrey Rublev vs. Felix Auger-Aliassime match. The winner of that match will have a real shot at making the semifinals, with both Rublev and Auger-Aliassime having battled through their own dramatic paths to the fourth round.
Betting markets have also zeroed in on the potential for a tight contest. Predictions point to the match exceeding 29.5 or even 31.5 total games, reflecting expectations that Riedi’s endurance and de Minaur’s counterpunching will produce extended rallies and possibly a four-set affair. One tipster put it succinctly: “I am confident Alex de Minaur will win, but Leandro Riedi’s recent performance makes the match intriguing. Riedi should get at least one set because of his qualifier momentum and his proven ability to bounce back in five-set matches.”
For Riedi, this match is already the highlight of his young career—a testament to perseverance and the unpredictable magic of Grand Slam tennis. For de Minaur, it’s another chance to prove why he’s considered one of the sport’s most reliable performers on hard courts, and to keep his hopes alive for a deep run in New York.
As the action unfolds on Labor Day in Flushing Meadows, all eyes will be on Court 17 as the underdog Swiss and the Australian favorite battle for a coveted quarterfinal spot. Will de Minaur’s experience and consistency win out, or can Riedi’s Cinderella story add another remarkable chapter? With both players in strong form and the tennis world watching, this Round of 16 clash promises fireworks and perhaps, just perhaps, another US Open surprise.
Stay tuned as the match gets underway—one thing’s for sure, the journey to the quarterfinals is anything but predictable this year.
