Northern Ireland's Michael Hoey carded an opening four-under-par 68 to sit four off the lead at the ISPS Handa World Super 6 in Perth in the innovative event, which features 54 holes of traditional strokeplay before the top 24 players compete in a six-hole knockout match-play format on Sunday.
Hoey celebrated his 40th birthday on Wednesday and will hope to toast the milestone with a good showing this weekend. He's part of a six-strong group on four-under after offsetting a couple of bogeys with six birdies.
Paul Dunne laboured to a one-over 73 after a patchy front nine which included three bogeys and two birdies. Gavin Moynihan is a further shot back.
Norway's Kristoffer Reitan and Miguel Tabuena of the Philippines shot 65s to share the lead.
After starting from the 10th at Lake Karrinyup, Tabuena birdied his first seven holes and picked up another shot on the 18th to race to the turn in just 28 shots.
The 24-year-old also birdied the first but could not maintain such a blistering pace and dropped shots on the fifth and ninth to finish seven under par alongside Reitan, who carded eight birdies and a bogey.
"My alarm was 3:30 in the morning, but it paid off and I'm pretty happy with my position," Tabuena said. "I love coming to Perth and it feels like home. The weather's similar, the courses are similar, and it's great to be back.
"I tried to keep it (his score) in the back of my head but it caught up to me on the third and fourth hole. I started to force some stuff, which I shouldn't have, and it cost me."
Reitan came through all three stages of the European Tour's qualifying school as an amateur last year. The world number 1,890 is playing just his fifth event since turning professional.
The 20-year-old said: "Last year I qualified for the US Open and qualified for the European Tour through Q-School, so it's something maybe with the qualifying mindset that I enjoy. I hope it can work to my advantage this week.
"Even if I play really bad I'm trying to learn something, and if I play well, it might be because I've learned something. So, I'm just trying to learn as much as I can from every tournament and try to unlock my best golf."
England's Richard McEvoy and New Zealand's Benjamin Campbell lie two shots off the lead.
