Maas recorded seven birdies and one bogey on his way to a 6-under 65 as the North Shore Country Club plays a par 71.
Maas started on hole No. 10 and shot a 32 on his first nine after making birdies on holes No. 12, 15, 16, and 17. He made a bogey on hole No. 1 as he made the turn, but then bounced back with birdies on holes No. 2, 3 and his final hole for the day, No. 9.
Maas said the swing changes ultimately paid off on the tree-lined fairways of North Shore because they set up consistent fades with the driver.
“There seem to be more doglegs to the right here, so that suits me perfectly,” Maas said. “It’s just hitting those big fades that help keep me in the fairway. That’s important with the long rough.”
Drew Goodman, who was paired with Maas in round one, adopted a similar fairway-first mentality, and it led to a nearly flawless opening round. Goodman is T2 after a round of 5-under 67.
Through 17 holes, Goodman was bogey-free with six birdies on his card, but a missed fairway and burnt edge on his par putt added a bogey to the tally on his final hole.
“I wasn’t planning on practicing after my round today, but that bogey gives me a little motivation to go hit a few balls now,” Goodman said with a smile. “Overall, I felt like I played pretty good, though. You’re just trying to survive and make that first cut, and however you cut it, 5-under is a good start.”
Matthew Riedel of Houston, Tex., Brendan Valdes of Orlando, Fla, and Gustav Frimodt of Denmark are all T2 after rounds of 5-under 66.
Valdes was one of two players to go bogey-free in round one.
2021 champion Michael Thorbjornsen of Wellesley, Mass., is T6 after a 4-under 67. Maxwell Moldovan of Uniontown, OH., is also T6 at 4-under.
Defending champion Austin Greaser is T51 after an even-par 71.
Caleb Surratt of Indian Trail, N.C., the 2021 Western Junior champion and reigning Elite Amateur Cup winner, is T13 after a round of 3-under 68.
Other notable round one scores are Nick Dunlap of Huntsville, Ala., at 2-under 69, Kazuma Kobori of New Zealand at 2-under 69, 2023 U.S. Junior Amateur champion Bryan Kim of Brookeville, MD., at 1-under 70, and Jackson Van Paris of Pinehurst, N.C., at 2-over 73.
Maas made history as the low amateur in the 2022 South African Open and is a rising sophomore at the University of Texas. Former Longhorn Beau Hossler won the 2014 Western Open.
CHRISTIAAN MAAS MAKES HISTORY AS LOW AMATEUR AT SOUTH AFRICAN OPEN The field will be cut to low 44 and ties after Wednesday's 18 holes.