The roof was figuratively caving in on two-time ‍defending Australian Open champion Jannik Sinner before he received help from above – literally.

Thanks in large part to a mid-match roof closure at Rod Laver Arena in Melbourne, Sinner got past the United States' Eliot Spizzirri 4-6, 6-3, 6-4, 6-4 on Saturday to reach the fourth round of the Australian Open.

Trailing Spizzirri in the third set and experiencing debilitating cramps in his arms and legs, Sinner rallied after play was suspended for about 10 minutes and the roof was closed due to sweltering conditions.

When play resumed, Sinner broke Spizzirri to get the set back on serve and went on to ‍prevail.

The suspension was prompted by the tournament's extreme heat policy. When the chair umpire ⁠made the announcement, Spizzirri was up 3-1 in the third set. The players left the court, and the ‍roof was shut.

"I struggled a bit physically," Sinner said after closing out the win. "I got lucky with the heat rule, when they closed the roof, I took my time. As time passed, I felt better and better."

"It started with the leg, then it got into the arms, so I was cramping a ‌bit all over, but this is the sport."

Sinner will meet fellow Italian Luciano Darderi for a place in the quarter-finals as he continues his bid for a third ‌consecutive title at Melbourne ⁠Park.

Sinner was one of three seeded Italian players who earned wins in the Saturday heat.

Fifth-seeded Lorenzo Musetti, the Hong Kong Open finalist, went the distance against Tomas Machac of the Czech Republic and prevailed 5-7, 6-4, 6-2, 5-7, 6-2 in a match that ‍took four hours and 27 minutes.

The 22nd seed Luciano Darderi beat 15th-seeded Russian Karen Khachanov 7-6(5) 3-6 6-3 6-4 to reach the fourth round of ‍a Grand Slam for the first time.

Also making it through to the next round was Ben Shelton, who has yet to drop a set, as the American eighth seed defeated Monaco's Valentin Vacherot 6-4 6-4 7-6(5). (Reuters)