For all the hype around the likes of Sinner, Sabalenka, Alcaraz and Swiatek at the opening major of the season, once more it was the old boys who were catching the eye on Day 5 in Melbourne.
First, 37-year-old former world No.3 Marin Cilic recorded his second successive straight-sets win to beat 21st seed Denis Shapovalov 6-4 6-3 6-2.
And later, the soon-retiring Stan Wawrinka was thrilling another packed KIA Arena, extending his last visit to Melbourne Park by edging a deciding tiebreak against young Frenchman Arthur Gea.
It was a significant victory for AO 2018 runner-up Cilic, who moved to 599 tour level wins to match fellow Croat Goran Ivanisevic for the most of any player from their country in the Open era.
“Just fantastic to be in this position,” said the 2014 US Open winner, who plays Casper Ruud in round three.
“Obviously different careers, different times. We are both different kinds of players. But also in order to achieve this number of victories you have to be so consistent for so many years.”
Three years Cilic’s senior at 40, Wawrinka’s emotional victory was even more impressive, outlasting his 21-year-old opponent from two sets to one down 10-3 in the deciding shootout after four hours and 33 minutes.
“I’m exhausted,” joked the three-time major winner, who will retire at the end of the season.
“It’s my last Australian Open, so I’m trying to last as long as possible.”
Another player appearing at the Australian Open for the final time is Romania’s Sorana Cirstea, but the 35-year-old former world No.21 had to settle for second-best against two-time AO champion Naomi Osaka. The Japanese former world No.1 survived in three sets 6-3 4-6 6-2 before a frosty handshake at the net.
Both defending champions were back in action on Thursday, and both are into the third round without dropping a set.
Madison Keys made it nine Melbourne wins on the bounce by beating Ashlyn Krueger 6-1 7-5, and Jannik Sinner moved to 16 victories in a row here after a comfortable outing against James Duckworth 6-1 6-4 6-2.
Keys was joined in the round of 32 by fellow top seeds Iga Swiatek, Amanda Anisimova, Elena Rybakina and Jessica Pegula, who all won in straight sets.
Likewise on the men’s side, there were no problems for most of the favourites expected to go deep in the draw.
Novak Djokovic moved to 399 Grand Slam match wins by outclassing Italian qualifier Francesco Maestrelli 6-3 6-2 6-2 during the Rod Laver Arena day session.
Lorenzo Musetti beat good friend Lorenzo Sonego, and American duo Ben Shelton and Taylor Fritz were strong in victories over Aussie Dane Sweeny and Czech Vit Kopriva respectively.
It wasn’t all plain sailing for the seeds though, with a big surprise in the women’s draw late on when 19-year-old Czech qualifier Nikola Bartunkova beat in-form 10th seed Belinda Bencic 6-3 0-6 6-4 for a first top 10 win.
Bencic was joined heading for the exit by 24th and 25th seeds Jelena Ostapenko and Paula Badosa, who both suffered second-round defeats on Thursday.
Former finalist Stefanos Tsitsipas also fell to Czech Tomas Machac, while young American Ethan Quinn had a great win over former top 10 star Hubert Hurkacz.