Jannik Sinner Surges Into Australian Open Quarterfinals After Tech Drama

Jannik Sinner’s relentless march through the 2026 Australian Open continued on Monday as the Italian star powered past compatriot Luciano Darderi, 6-1, 6-3, 7-6(2), to book his place in the quarter-finals for the fourth time at Melbourne Park. The world No. 2, who has now reached nine consecutive Grand Slam quarter-finals, put on a serving masterclass and showcased his growing versatility on court, but the match wasn’t without its share of drama—both on and off the court.

Just moments before the opening serve, Sinner found himself in the middle of a minor controversy. Umpire Greg Allensworth spotted a banned Whoop fitness tracker hidden beneath Sinner’s wristband as the players approached for the coin toss. Without protest, Sinner removed the device, which is permitted on the ATP and WTA tours but remains prohibited at Grand Slam events like the Australian Open. Sinner later explained, “The umpire asked me straightaway, if this is the tracker. I said yes. He said remove. It’s fine. There are other things we could use. The vest [with tracker inside]. But it’s a bit for me uncomfortable. You feel like you have something on the shoulders. It’s a bit different. But rules are rules. I understand. I won’t use it again.”

The incident highlighted an ongoing debate in tennis about the use of wearable technology. Although the International Tennis Federation (ITF) has approved the Whoop device for in-match wear, Grand Slam organizers like Tennis Australia continue to ban it, citing regulatory concerns. A Whoop spokesperson responded, “Whoop believes athletes have a fundamental right to understand their own performance and health—including during competition at events like the Australian Open. Whoop is approved by the International Tennis Federation for in-match wear and poses no safety, fairness, or competitive risk. Blocking access to personal health data does not protect sport. Whoop will continue to stand with athletes and our members to defend their right to their data.”

Back on court, Sinner wasted little time asserting his authority. He raced through the opening two sets, mixing clinical baseline play with a newly refined serve that yielded a career-best 19 aces and, notably, zero double faults. His power and consistency kept Darderi, playing his first official head-to-head against Sinner, largely on the back foot. The match, which lasted two hours and nine minutes, saw Sinner rack up 46 winners and extend his unbeaten record against fellow Italians to a remarkable 18-0 on tour.

"It was very, very difficult. We’re good friends off the court," Sinner said of his opponent. "Third set I had some break chances, I couldn’t use them. I got tight, so very happy I closed it in three sets." The third set did indeed see a shift in momentum. Darderi, suddenly swinging with more aggression, earned four break points at 4-4 and even led 2-0 in the tiebreak. But Sinner, unfazed by the mounting pressure—or a brief interruption from a crying baby in the crowd—reeled off seven straight points to clinch the victory. "We are good friends off the court. It’s also that, a small difficulty to put away. I felt like in the third set I had a couple of great chances, I couldn’t use them and then I got very, very tight, so I’m very happy that I closed it in three sets," Sinner reflected.

This victory was particularly sweet for Sinner after his struggles in the previous round. On Saturday, he had battled both Eliot Spizzirri and the brutal Melbourne heat, suffering from cramps and only regaining control after the tournament’s extreme heat policy forced an eight-minute roof closure and a ten-minute cooling break. Sinner later admitted, “I got a bit lucky with the timing of the extreme heat policy being invoked.” His coach, Darren Cahill, provided further insight: “The recovery has been pretty normal in the last 48 hours. He woke up yesterday feeling pretty good but not great.”

Coach Cahill also revealed that Sinner had been offered a different scheduling slot for the Darderi match but chose to stick with the original plan. “We could have been moved to the night session when Mensik pulled out. It was offered to Jannik to move to that second at night, but he was quite happy with the schedule when it came out, that he was here not before 6pm on Margaret Court, so we just stuck to the schedule. There is no problem whatsoever for Jannik playing in this stadium.”

The Italian’s form has been steadily improving with each round. Sinner credited his off-season work, particularly on his serve, for his recent success. “We put a lot of work in, especially with the serve. We changed the motion a bit and I feel for sure a little bit more confident. There is still room to improve, which is normal, but I’m very happy with how I have come back in the new season. At the end of last season, I served really well, [and] it’s much more stable.”

With this latest win, Sinner joins Grigor Dimitrov, Kei Nishikori, and Stefanos Tsitsipas for the fourth-most Australian Open quarter-final appearances among active players. He also stands as the third youngest player to reach nine consecutive Grand Slam quarter-finals—a testament to his consistency and resilience on the sport’s biggest stages.

Looking ahead, Sinner will face American Ben Shelton in the quarter-finals, after Shelton edged out Casper Ruud in a hard-fought fourth-round battle. Sinner is aiming to join Novak Djokovic as the only men to capture three consecutive Australian Open titles in the Open Era. The prospect of a potential semi-final clash with Djokovic is already generating buzz among fans and pundits alike.

Despite the pre-match wearable tech kerfuffle and a brief late wobble, Sinner’s performance against Darderi sends a clear message: the defending champion is not only surviving the pressures of the Grand Slam grind, but thriving. As he put it himself, “Let’s see what’s coming in the next round.” With his blend of power, poise, and ever-improving tactics, Sinner remains very much the man to beat in Melbourne.