Qualifying medalists Sam Horsfield and Sean Crocker each won two matches Thursday in the U.S. Junior Amateur to advance to the quarterfinals at The Club at Carlton Woods.
The 17-year-old Horsfield, from England, beat South Korea's Won Jun Lee 3 and 2 in the second round, and topped Australia's Zach Murray 1 up in the third.
The 17-year-old Crocker, from Zimbabwe, beat John Augenstein of Owensboro, Kentucky, 3 and 2, and edged Sahith Theegala of Chino Hills, California, in 20 holes.
On Friday on the Nicklaus Course, Horsfield will face Norway's Andreas Halvorsen in the upper-bracket quarterfinals, and Crocker will play William Zalatoris of Plano, Texas, in the lower bracket. In the third round, Halvorsen beat Davis Shore of Knoxville, Tennessee, 4 and 3, and Zalatoris edged Will Dickson of Providence, Rhode Island, 1 up.
In the other quarterfinals, Will Grimmer of Cincinnati will play Australia's Curtis Luck in the upper bracket, and Davis Riley of Hattiesburg, Mississippi, will face China's Andy Zhang in the lower bracket.
In the third round, Grimmer beat Anton Serafini of Lake Mary, Florida, 2 up; Luck routed Joshua McCarthy of Danville, California, 5 and 4; Riley topped Aaron DeNucci of Clive, Iowa, 2 and 1; and Zhang beat Doc Redman of Raleigh, North Carolina, 1 up.
The semifinals are Friday afternoon, and the final is set for Saturday.