Jannik Sinner put aside concerns about his ability to withstand the heat with a dominant 6-1, 6-3, 7-6 victory over fellow Italian Luciano Darderi on Monday.
With the temperature soaring to 33 degrees Celsius in the evening match at Margaret Court, all eyes were on the defending champion after the muscle strain he suffered in the third round on a hot day against American Elliott Spezery.
But there were no signs of problems today as Sinner ran full power from start to finish against 22nd-ranked Dardery and secured a comfortable victory in just two hours and nine minutes.
Sinner said after the match, "It was very difficult. First of all, we are very good friends off the court. I felt very tired (in the third set), so I am very happy that I finished the match in three sets."
While the unseeded Spiezieri was a source of fear for Sinner with his composure and strength, the Argentine-born Dardery made the champion's task much easier by not shining in the first two sets.
Sinner raced to a 5-0 lead in the first set before Dardery finally held his serve in his first Grand Slam round of 16 appearance.
Sinner responded by holding his serve without giving his opponent a single point and finished the set in 27 minutes with his 12th successful shot, a massive forehand that touched the sideline.
In the third game, Dardery completely lost his composure and threw his racket to the ground when he unforced an inept backhand shot that went over the baseline of the court.
He then hit a long forehand to lose his serve on the next point and launched a ball high towards the stands to receive a warning for misconduct.
Sinner will meet the winner of the match between Ben Shelton and Casper Rudd to qualify for the semi-finals.
