Lin, who played in the Junior Presidents Cup at Royal Melbourne in 2019, carded six birdies and just two dropped shots to surge up the leaderboard.
“It was definitely a good day of business,” said Lin, who goes by C.T. “Today I start by just hitting a lot of good shots, and sometimes putts drop, sometimes they don't. But just try to hang in there; it's definitely more scorable in the morning compared to the wind yesterday.”
Ding made a fast start with two birdies in his opening four holes but slipped back with bogey fives at the fifth and seventh. The freshman at Arizona State bounced back with birdies at Holes Nos. 10 and 13 but was disappointed to drop a shot at the last.
New Zealanders Kazuma Kobori and Jimmy Zheng were hard on their heels after enjoying varying second-round fortunes.
First-round leader Kobori started brightly with a birdie at the par-4 fourth on the Royal Melbourne Composite Course but ran into trouble with four dropped shots in five holes from the seventh hole on.
Zheng made his move with birdies at Holes No. 2, 4, 10, and 12 but tripped up with a bogey at No. 14. His 2-under 69 left him one under for the Championship.
Billy Dowling is the leading Australian at one under after returning a 2-over round of 73, even with Kobori, Zheng, and Indonesia’s Randy Bintang and T3 overall.
The cut fell at 12-over par 154, with 67 players making it through to tomorrow’s third round.
The Asia-Pacific Amateur field comprises 120 of the top male amateurs from the Asia-Pacific region. The 2023 field features players from 37 nations, all competing to secure an exemption into The Open and an invitation to the Masters Tournament in 2024.
The Championship was created in 2009 by the Masters Tournament, The R&A and the Asia-Pacific Golf Confederation in an effort to further develop amateur golf throughout the region.