He shapes as the big winner out of Novak Djokovic's extraordinary Australian Open exit and Matteo Berrettini is already cashing in at Melbourne Park.
The Wimbledon runner-up eased into the second round on Monday with a 4-6 6-2 7-6 (7-5) 6-3 win over American Brandon Nakashima.
The highest-ranked player in a quarter of the draw blown wide open by Djokovic's dramatic deportation from Australia, Berrettini suddenly looms as a likely semi-finalist.
Djokovic has been the Italian's grand slam nemesis, taking Berrettini out in four tough sets in the quarter-finals of the French and US Opens either side of their Wimbledon title decider last year.
But with his lucky loser compatriot Salvatore Caruso replacing Djokovic atop the draw and 12th seed Cameron Norrie crashing out in the first round, Frenchman Gael Monfils and Chilean Christian Garin are now the only top-20 rivals in Berrettini's section.
Five-times finalist and 2009 champion Rafael Nadal staked his claim to be a potential semi-final roadblock to Berrettini with a 6-1 6-4 6-2 drubbing of Marcos Giron in his opener.
Berrettini's immediate focus, though, will be Wednesday against American wildcard Stefan Kozlov, a straight-sets first-round winner over Jiri Vesely.
Norrie bombed out 6-3 6-0 6-4 to Sebastian Korda in his opener, after Monfils and Garin both advanced in contrasting fashion on day one.
Garin, the 16th seed, survived a five-set scare against Argentine Facundo Bagnis before escaping with a 6-3 6-4 5-7 6-7 (4-7) 6-3 in the all-South American affair.
Monfils, the 17th seed, allayed fears over a neck injury with a 6-1 6-1 6-3 rout of Federico Coria.
Earlier, Spanish prodigy Carlos Alcaraz made a lightning start to the Open, storming into the second round in less than two hours.
Playing his first match of the year after a brush with COVID-19, the 31st seed was untroubled in beating Chilean qualifier Alejandro Tabillo 6-2 6-2 6-3 on Monday.
At 18, Alcaraz is the youngest player in the men's draw and somewhat unfairly carries the burden of being hailed as the next Rafael Nadal.
But the teenager did little to temper expectations, backing up his charge to last year's US Open quarter-finals with an ominous opening to the Melbourne Park grand slam.
That will come against Serb Dusan Lajovic on Wednesday for a place in the last 32.
Fellow young gun Denis Shapovalov also safely progressed but not without a battle.
The 14th seed needed four sets and two tiebreakers to see off Laslo Djere 7-6 (7-3) 6-4 3-6 7-6 (7-3) after three hours and 23 minutes.
Canada's newly crowned ATP Cup winner set up a second-round clash with Korean Soonwoo Kwon, while Caruso's cameo in Djokovic's coveted slot was just that as the Italian succumbed 6-4 6-2 6-1 to Miomir Keomanovic.
