Fifth seed Grigor Dimitrov made an impressive start to his campaign at the ATP Brisbane International with a straight sets victory over Holland's Robin Haase.
The Bulgarian - who reached last year's final before losing to Andy Murray - proved far too strong for his Dutch opponent, emerging a comfortable 6-2 6-3 victor.
Meanwhile, there was a landmark moment for home hope Marinko Matosevic as he recorded his first-ever ATP win on home soil.
The 28-year-old Australian was made to work for his success, but eventually outlasted France's Julien Benneteau to complete a gruelling 5-7 6-4 7-6 (7/4) triumph.
Finland's Jarkko Nieminen set up a second round clash with top seed Roger Federer after beating Matosevic's compatriot James Duckworth 6-2 6-3.
Seventh seed Dmitry Tursunov made an early exit as he was upset by Sam Querrey, the big-serving American claiming a 7-5 6-4 win.
Meanwhile, Marin Cilic had to dig deep before finally seeing off Denis Istomin after another hard-fought three-set encounter - the Croatian coming through 6-7 (3/7) 7-6 (7/5) 6-4.