With the threat of the Big Three looming ever-large over Melbourne Park, challengers Dominic Thiem and Roberto Bautista Agut have easily negotiated their first-round Australian Open assignments.
Two-time French Open runner-up Thiem vaulted into the second round with a comfortable 6-3 7-5 6-2 win over Adrian Mannarino while Bautista Agut breezed past countryman Feliciano Lopez.
Seventh-seeded German Alexander Zverev also eased through with a late night 6-4 7-6 (7-4) 6-3 win over Italian Marco Cecchinato, while Russian fourth seed Daniil Medvedev prevailed in an entertaining four-set encounter with young American Frances Tiafoe.
Austrian fifth seed Thiem has underachieved at the Australian Open, having never been past the fourth round in six previous attempts.
With Australian wildcard Alex Bolt his second round opponent, Thiem is rated one of the biggest threats to Rafael Nadal, Novak Djokovic and Roger Federer this campaign.
Three-times grand slam winner Stan Wawrinka, the Melbourne Park champion in 2014, also progressed, 7-5 6-7 (4-7) 6-4 6-4 over Damir Dzumhur and will now face Italian Andreas Seppi.
Runner-up to Federer two years ago, dangerous unseeded floater Marin Cilic blitzed Frenchman Corentin Moutet.
The giant Croatian smashed 34 winners and dropped just one service game in setting up a second-round date with temperamental Frenchman Benoit Paire.
Cilic, the 2014 US Open champion, looks on a third-round collision course with ninth seed Bautista Agut, who firmed as a tournament dark horse with a seventh-straight win of the summer.
Bautista Agut, unbeaten through Spain's run to the ATP Cup final, dispatched Lopez 6-2 6-2 7-5.
The Spaniard will return on Wednesday to play American wildcard Michael Mmoh.
Canadian Milos Raonic, who lost to Andy Murray in the 2016 Wimbledon final, also had little trouble closing out his rain-delayed encounter over lucky loser Lorenzo Giustino 6-2 6-1 6-3.
If he beats Chile's Christian Garin next, Raonic will likely play last year's breakout semi-finalist Stefanos Tsitsipas for a spot in the last 16.
Diminutive Argentinian 14th seed Diego Schwartzman cruised past South African Lloyd Harris, while Italian teen sensation Jannik Sinner outgunned Australian qualifier Max Purcell 7-6 (7-2) 6-2 6-4.
Fiery Italian 12th seed Fabio Fognini survived a fifth-set super-tiebreaker to progress 3-6 6-7 (7-3) 6-4 6-3 7-6 (10-5) over big-serving American Reilly Opelka and set up a clash with Aussie Jordan Thompson.
Polish 31st seed Hubert Hurkacz will also meet a local, John Millman, next up after fighting back from two sets down to beat Austrian qualifier Dennis Novak.
But 20th-seeded whiz kid Felix Auger-Aliassime wasn't so lucky, losing to Latvian qualifier Ernests Gulbis 7-5 4-6 7-6 (7-4) 6-4 to join fellow Canadian Denis Shapovalov on the scrapheap.
Australian Associated Press