Jannik Sinner battled debilitating cramp and 40-degree heat to reach the Australian Open fourth round, defeating American Eliot Spizzirri 4-6 6-3 6-4 6-4. The defending champion's hopes were saved when the extreme heat policy was invoked, allowing the roof on Rod Laver Arena to close.

Sinner limped to his players' box mid-match, receiving advice from coach Darren Cahill. With his serve broken and trailing, the tournament's heat stress scale hit five, triggering the stoppage. The reprieve proved decisive, as Sinner broke Spizzirri twice to reclaim control of the match.

The Italian admitted he was "lucky" with the timing, acknowledging his physical struggles. He will next face compatriot Luciano Darderi in the last 16, marking the first time three Italian men have reached this stage at Melbourne Park. His performance, while gritty, highlighted ongoing concerns about his endurance in extreme conditions.