China's Dou Zecheng beat fellow 16-year-old Sam Horsfield of England 1-up Thursday in the US Amateur Public Links to advance to the quarterfinals.
Dou took the lead with a par on the par-3 16th at Laurel Hill and matched Horsfield with a par on the par-4 and a birdie on the par-5 18th to close out the match.
''This is my best match ever,'' Dou said. ''We barely had any missed shots. It was fun because I've been playing with Sam since I was 7 years old, so we know each other well. This is a great memory.''
Dou, a 3-and-2 second-round winner over Sam Saunders of Albuquerque, NM, in the morning, will face Oklahoma State sophomore Jordan Niebrugge of Mequon, Wis. Niebrugge beat Canada's Justin Shin 5 and 3 in the third round and has played a tournament-low 44 holes in match play.
In the other upper-brack quarterfinal, 19-year-old Austin Smotherman of Loomis, Calif., will play James Erkenbeck of San Diego.
Smotherman beat 51-year-old Sean Knapp of Oakmont, Pa., 4 and 3.
''I've heard a lot about (Knapp). I mean, he's played in 14 US Amateurs,'' Smotherman said. ''But you can only control yourself, so that's what I focused on though it does feel good to beat a good player.''
Erkenbeck, at 23 the oldest player remaining, topped Mexico's Mario Clemens 5 and 4.
''I never feel comfortable no matter how big the lead is,'' Erkenbeck said. ''You know not to give away holes, but at the same time you don't want to change too much of what you're doing because that's what got you the lead in the first place.''
In the lower bracket, Robby Shelton IV of Wilmer, Ala., will face Michael Kim of Del Mar, Calif., while Eric Sugimoto of San Diego will play Kyle Henning of Brookfield, Wis.
Shelton beat Ian Davis of Edmond, Okla., 2 up; Kim advanced with a 3-and-2 victory over Mitchell Rutledge of Creve Coeur, Mo.; Sugimoto edged Cameron Peck of Olympia, Wash., 2 up; and Henning won the last two holes to beat Carlson Cox IV of Church Hill, Tenn., 1 up.
The tournament is limited to players who don't hold privileges at any course that doesn't extend playing privileges to the general public. The 36-hole championship match is Saturday.
