Jannik Sinner’s title defense is still alive, but the Australian sun and a fearless opponent pushed him as hard as anyone has this fortnight. The No. 2 seed and two-time defending champion fought through cramps, a heat suspension, and even a time-violation flashpoint to defeat American Eliot Spizzirri 4-6, 6-3, 6-4, 6-4 in a third-round battle that lasted 3 hours and 45 minutes on Rod Laver Arena.

It was not pretty early. It was gutsy late. And it was a reminder that champions do more than hit winners; they find a way when the match turns messy.

Rod Laver Arena delivers a rollercoaster

Sinner, 24, entered Saturday having won 26 straight sets at the Australian Open. That run ended fast. Spizzirri broke him three times in the opening set, taking it 6-4 as the Italian fired 37 unforced errors through roughly two-and-a-half sets. Sinner looked out of rhythm and often slow between points. Spizzirri, also 24 and playing his first Australian Open main draw and first Top-10 opponent, was steady and brave, especially off the backhand.

By the third set, Sinner’s body was screaming. Cramps hit both arms and legs. He trailed 3-1, limping between points and stretching on changeovers. Coach Darren Cahill’s message was simple and calm: “We just need to get to the end of this set. Even if you walk around, it’s okay. We get a break.”

“Is Sinner human after all? That first set looked mortal.”

Extreme heat and a timely pause change the tone

At about 2:35 p.m. local time, the Extreme Heat Rule kicked in as temperatures rose above 36°C (97F). Tournament officials suspended play to close the roof and allowed an 8–10 minute break. Outdoor courts were halted for more than three hours.

The timing favored Sinner. The pause let the trainer work on his calves and gave him a mental reset. When play resumed under the roof, the defending champion looked renewed. He chased down drop shots again. He moved with less fear. He broke back and turned the third set into a 76‑minute grind that ended 6-4, sealed with an ace in a hold to love.

From there, the script felt familiar. Sinner managed the fourth set with cleaner patterns and fewer dips, taking it 6-4 to end a bruising afternoon. A 10-minute cooling break between the third and fourth sets, as allowed by the conditions, further steadied the Italian.

“Heat break or champion’s nerve? Either way, Sinner solved it.”

Sportsmanship amid the time-violation drama

There was another twist in the second set. Sinner received a time-violation warning for slow serving. It might have sparked anger, but instead it brought a rare show of class. Spizzirri told the chair he wasn’t ready to receive and asked the umpire to rescind the warning. It was a small moment in a long day, yet it mattered. Respect ran both ways.

Sinner returned the favor with praise afterward. “It’s great. And um yeah, so let’s see what’s coming,” he said of moving on, before adding about the conditions, “Really hot out there…” On Spizzirri: “he was uh moving very well and especially with the backhand not missing uh barely any shots… great balance uh of of how much he should go for.”

Spizzirri’s level earned that respect. He trained with Sinner in the offseason and played with belief. Through the heat suspension, he had only 13 unforced errors, keeping rallies honest and forcing Sinner to find answers under pressure.

The numbers: breaks, errors, and a 76-minute swing set

• Final score: Sinner def. Spizzirri 4-6, 6-3, 6-4, 6-4.
• Match time: 3 hours, 45 minutes.
• Third set duration: 76 minutes.
• Sinner was broken six times overall (three in the first set).
• Sinner chalked 37 unforced errors mid-match; Spizzirri had 13 before the stoppage.
• Heat reached above 36°C (97F), triggering roof closure and a pause around 2:35 p.m. local time.

These figures tell the story of a champion who had to win ugly. They also underline how a brave challenger turned a marquee court into a fight. For Spizzirri, this was a debut third round at a major and a first taste of the sport’s elite. He did not blink.

“If this is Sinner at 70%, the rest of the field should worry.”

‘I’m not done yet’: Sinner’s message to Melbourne

On court, Sinner spoke straight to the fans: “I’m not done yet. I hope you guys come back in two days time, because I’ve still got a lot to prove here.” He also urged the crowd to stay cool in the heat. The 24-year-old Italian, 191 cm tall and coached by Darren Cahill and Simone Vagnozzi, has built his brand on control and calm. Today he needed both—and a little luck from the weather.

Sinner’s resume is star bright for a player still early in his prime: World No. 2, back-to-back Australian Open titles (2024 and 2025), a career record of 321-86, and more than $56 million in prize money. This match did not add style points. It added grit. And as the tournament moves deeper, grit often matters most.

What this means for the title defense

Next up is Luciano Darderi in the round of 16. It is another test, but Saturday’s survival may serve Sinner even better than a clean sweep. He has felt the heat. He has handled a body scare. He has stared down a red-hot opponent who trained with him and knew his habits.

After the win, Sinner summed up the day with a shrug and a smile: “It’s great. And um yeah, so let’s see what’s coming.” That felt right. The draw will only get tougher from here. But he leaves Rod Laver Arena with momentum and the belief that even on an off day, under a closed roof and a blazing sun, his floor is still high.

Who is Eliot Spizzirri, and what did we learn?

The American deserves a spotlight. At 24, in his first Australian Open main draw and first third round at a major, Spizzirri showed poise and patience. He attacked smartly, defended cleanly, and used his backhand as a rock. He also showed character by speaking up during the time-violation moment. That kind of detail earns fans and locker-room respect.

Spizzirri did not leave with the upset, but he left a mark. Against the two-time defending champion, on the biggest court in Melbourne, he made the match about his terms for long stretches. That is a big step in any career.

Final word

The day began with a streak snapped and a champion in trouble. It ended with Jannik Sinner waving to a grateful crowd and reminding everyone, “I’m not done yet.” In between, there was a heat stoppage, cramps, a 76-minute tug-of-war set, and a small act of sportsmanship that will be remembered.

That is tournament tennis in Melbourne: the sun can change the script; the roof can change the feel; the champion must change the result. Sinner did all three, and he moves on.