A trio of Australians - Kim Felton, Scott Gardiner and Bradley Hughes - each posted rounds of 4-under-par 68. They share fifth place with New Zealander Gareth Paddison and American Kyle Thompson.
Alaban got off to a quick start with a birdie at the par-5 10th. He then dropped in an eagle at the par-5 14th and moved to 4 under with a birdie at the par-3 16th.
Around the turn, Alaban sank a birdie try at the first, before birdieing the par-5 fifth. He stumbled to a bogey at the very next hole though. He grabbed first place by converting a birdie at the ninth, his 18th.
Jones opened on the front side with birdies at Nos. 2 and 5, both par-5s. He closed his opening nine with a birdie at the ninth. He came right back to birdie 10. Jones cruised to the house with seven straight pars before a birdie at the last.
Mills roared out of the gate as he birdied each of the first three holes. He dropped in another birdie at the fifth. He collected his final birdie of the day at the 10th, before parring in.
Scherrer, one of the earliest starters, birdied the par-4 12th, his third to open his round. He then notched back-to-back birdies from the 14th and closed out his first nine with a birdie on No. 18.
Around the turn, he dropped a shot at the first. Scherrer battled back with birdies at the third and fifth to get back to minus-5. He dropped another stroke at the seventh, but responded with a birdie at the next to share second place.
Doug Barron and Barry Cheesman carded rounds of 3-under-par 69 to head a group of 11 players tied for 10th. They are joined there by Ahmad Bateman, Chris Anderson, Craig Jones, Michael Long, Bill Lunde, Leigh McKechnie, David Smail, Aaron Townsend and Nick Watney.
Steven Alker and Paul Claxton, a pair of former winners, head a large group of players one stroke further back at minus-2.