Heat stress scale

Rod Laver Arena: Jannik Sinner’s Australian Open title defence was pushed to the brink on Saturday, but the World No. 2 dug deep to navigate extreme conditions and a fearless opponent, defeating American qualifier Eliot Spizzirri 4–6, 6–3, 6–4, 6–4 to reach the fourth round at Rod Laver Arena.

Sinner’s resilience was tested most severely midway through the match. After splitting the opening two sets, Spizzirri surged ahead 3–1 in the third as Sinner began to visibly struggle with cramping, his movement and service motion clearly compromised in the oppressive Melbourne heat. With the Heat Stress Scale reaching Level 5, officials intervened and ordered the roof closed, triggering a temporary suspension of play.

The short interruption proved pivotal. When play resumed after less than 10 minutes, Sinner looked revitalised. Drawing on his experience and composure, the four-time major champion steadied himself, clawed back the third set, and ultimately completed the victory after three hours and 45 minutes of attritional tennis.