Novak Djokovic started his Australian Open title defence with a crushing win against Paolo Lorenzi of Italy.
The top seed overturned an early break of serve and went on to win 6-2 6-0 6-0 in an hour and 32 minutes to seal a meeting with Santiago Giraldo.
Earlier, fifth seed David Ferrer beat Rui Machado 6-1 6-4 6-2, and next plays America's Ryan Sweeting.
Andy Murray, Andy Roddick, Jo-Wilfried Tsonga and Lleyton Hewitt are also safely through.
"It was a great performance for my first official match of the 2012 season," said two-time champion Djokovic.
"It's great to come back to Melbourne; I have great memories here.
"Nowadays I'm a more complete player. I feel I know what to do on court.
"I'm physically stronger, move better, have improved my strokes and serve better - that gives me a lot of confidence."
Roddick, seeded 15, made easy work of Robin Haase in winning 6-3 6-4 6-1.
He will meet local favourite Hewitt, who claimed a 7-5 6-4 3-6 7-5 win over Cedrik-Marcel Stebe in round two.
Hewitt said: "I hung in there and kept making him play as he is one of the young guys on tour and he got a little tight serving for the set twice."
Tsonga, the sixth seed, needed four sets to see off Denis Istomin, eventually winning 6-4 3-6 6-2 7-5, to set up a second round clash with Brazilian Richard Mello.
Frenchman Gael Monfils also made it safely through to round two with a 7-6 (7-5) 6-3 6-3 win over Australian wildcard Marinko Matosevic and will face Thomaz Bellucci in the second round.
Janko Tipsarevic, the number nine seed, beat Dmitry Tursunov 5-7 7-6 (14-12) 6-3 6-4, while Germany's Philipp Petzschner thrashed Lukas Rosol of the Czech Republic 6-0 6-0 6-2.
Richard Gasquet, seeded 17, overcame Andreas Seppi in four sets, while 24th seed Kei Nishikori of Japan beat France's Stephane Robert 6-1 7-6 (9-7) 6-0.
Elsewhere, 26th seed Marcel Granollers overcame a late fightback to sneak past Jesse Levine in five sets, while Radek Stepanek, Juan Ignacio Chela and Alex Bogomolov Jr went through.
Australian youngster James Duckworth, ranked 250th in the world, beat Jurgen Zopp 6-3 6-3 6-4 and has been rewarded with a second-round tie against Tipsarevic.