Perth's Min Woo Lee, Wodonga's Zach Murray, Sydney's Harrison Endycott and the Hunter Valley's Dylan Perry all won overnight at Royal St George's, giving Australia one of its deepest representations at this level of one the world's great amateur titles.
Reigning US Boys' Amateur champ Lee took down dangerous Irishman Conor O'Rourke 3&2, then Victorian captain Murray took down Argentina's Andres Gallegos 2&1.
Endycott won a tough battle 1-up over Dutchman Lars Keunen, while NSW state teammate Dylan Perry was impressive in toppling German Michael Hirmer.
Endycott, a member of Australia's Eisenhower Cup winning team last year, was thrilled to get through given he hadn't played his brilliant best.
"It wasn't the best, but I did a great job of getting it done," the Avondale member said.
"But I made stuff happen when I had to … just by hitting some good shots to put the pressure on."
On the downside, Travis Smyth lost a thriller on the 19th hole to Swiss Perry Cohen, Blake Windred lost 5&4 to Kristoffer Ventura and Ben Ferguson fought hard but went down 3&2 to last year's runner-up Rob MacIntyre.
The round of 32 begins late this afternoon Australian time.