The Republic of Ireland’s Paul Dunne, who shared the 54-hole lead in The Open Championship at St. Andrews, and United States Walker Cup Team member Bryson DeChambeau each won two matches Thursday and will meet in the quarterfinals of the 2015 U.S. Amateur Championship at Olympia Fields Country Club’s North Course.

To advance to Friday’s quarterfinals, DeChambeau, 21, of Clovis, Calif., defeated Walker Cup teammate and 2015 Jack Nicklaus and Haskins Award winner Maverick McNealy, of Portola Valley, Calif., 3 and 2, in the Round of 16 after beating University of South Carolina All-American Matt NeSmith, 5 and 4, in the morning’s Round of 32.

“I've tried nine times in USGA amateur events, and I've qualified for match play in every single one of them and gotten to the quarterfinals only in the Public Links last year,” said DeChambeau, a first-team All-American from Southern Methodist University who won the NCAA Division I individual title. “So to make it to the quarterfinals in the Amateur is pretty special, something that I've wanted to do for quite a long time now.”

Dunne, who became the first amateur to hold or share the 54-hole lead at The Open Championship since the legendary Bob Jones in 1927, defeated David Oraee of Greeley, Colo., 3 and 2, in the Round of 16. In the morning, he topped Caleb Proveaux, of Lexington, S.C., 3 and 2.

“I didn't think I'd get the experience of playing in the final group of The Open, but it's something I'm grateful to have done,” said Dunne, a recent graduate of the University of Alabama-Birmingham who finished fifth at the NCAAs and earned All-American honors. “I knew I could shoot the scores I needed in order to play as well as I have. I just didn't know it would put me in the situations it has. But for the amateur stage, I knew that I'm good enough that if I play well, I can compete in any amateur event.”

Dunne, 22, who accepted a special exemption into the championship from the USGA, assessed his quarterfinal opponent: “He does things a little differently to everyone else, but he obviously does it really well. He's got a great game. I'm sure it'll be a good match tomorrow. It'll be a tough match, but I know if I do the things I can do and play my game that I'll have a good chance.”

The other quarterfinal match-ups are: Kenta Kinoshi, 21, of Japan, who once defeated Hideki Matsuyama in a Japanese amateur tournament, against Baylor University sophomore Matthew Perrine, 19, of Dallas, who played together in the stroke-play qualifying; 2015 Sunnehanna Amateur champion Derek Bard, 20, of New Hartford, N.Y., against World Amateur Golf Ranking No. 1 and Ben Hogan Award winner Jon Rahm, 20, of Spain; and Canada’s Austin James, 19, against Sean Crocker, 18, of Westlake Village, Calif., who holds American and Zimbabwean citizenship.