Spain's Alejandro Canizares and New Zealand's Michael Hendry each shot 7-under 65 on Thursday to share the first-round lead in the Perth International.
Canizares had seven birdies in a bogey-free round at Lake Karrinyup, and Hendry put together five birdies on his second nine. Argentina's Emiliano Grillo was a stroke back, and Englishmen Paul Casey and Andrew Johnson shot 67 in the event sanctioned by the European Tour and PGA Tour of Australasia.
South Africa's Charl Schwartzel and American Jason Dufner were tied for 29th at 71.
Canizares, who won the last of his five European Tour titles in 2006, chipped in for a birdie on the par-3 eighth hole and added three on the back nine.
"It was a good round," Canizares said. "I hit the ball really well and made some putts, so I'm really happy. I played pretty steady the whole round and gave myself plenty of chances. I think I only missed two greens in the whole round."
The 574th-ranked Hendry has missed five straight cuts on the Australasian and OneAsia tours since winning the New Zealand PGA Pro-Am Championship earlier this year.
"When you're playing bad and you're spending lots of money to get to events and not getting a lot of return on that investment, it does put a lot of pressure on you to play well," Hendry said.
Grillo is trying to secure his European playing rights for 2013.
"I hit a lot of fairways out there, that's very important on this golf course, and a lot of greens. And then the ones that I missed, I got up and down," Grillo said. "So, it was a good round overall. There are not many tournaments left, so I'm trying to make as much ground as I can this week."
Casey continues to rediscover his form after dislocating his right shoulder in a snowboarding accident after the end of last season.
"I played wonderful golf today," Casey said. "I'm really happy with 67. I thought the golf course would be trickier this afternoon. ... I wasn't out this morning, but I'm going to assume it was slightly trickier this afternoon. Tee to green was beautiful, and I'm ecstatic with the number of birdie chances I had."