The Louisville senior defeated USA Walker Cup team member Chris Kirk 7 and 6 in the second round, then dominated stroke medalist Jason Kokrak 6 and 4 in the afternoon to advance to Friday's quarterfinals.
'I'm playing pretty solid,' Fathauer said. 'This morning I was pretty much given a lot of holes ... and this afternoon (it was) just about the same thing. I made a few putts and just played solid.'
Also advancing were Michael Thompson, Cheng Tsung Pan, Jhonattan Vegas, Casey Clendenon, Eddie Olson, Nick Taylor and Colt Knost.
Thursday's eight winners will play in the quarterfinals, with the semifinals slated for Saturday. Two golfers will then square off in Sunday's 36-hole final, with the winner receiving an automatic berth in the 2008 U.S. Open and British Open.
Fathauer never trailed Thursday, making birdie on the first hole in each match. Against Kirk, the Ben Hogan award winner as the top college golfer in the country, he had three birdies and one bogey and took advantage of a tough round by Kirk, who bogeyed five of the first seven holes and finished with eight bogeys overall.
It was much of the same against Kokrak. Fathauer had four birdies and one bogey, while Kokrak struggled with three bogeys and one double-bogey.
'I just didn't feel the same way as I did this morning,' said Kokrak, who beat Mark Harrell 2 and 1 in the second round. 'Today I just didn't have my 'A' game.'
Fathauer will play Thompson in Friday's quarterfinals. Thompson defeated Bryce Ledford 3 and 2 in the second round then came back to beat David McDaniel 2 and 1 in the afternoon.
'We know each other pretty well,' Thompson said of Fathauer. 'I know he's been playing excellent here. It's going to be a really hard match, but I'm playing well and I'm looking forward to it.'
Fathauer likes his chances but isn't looking ahead. He did that at the Amateur Public Links championship in July when he was 2-up with five holes to go in the semifinals and wound up losing 1-up to Cody Paladino.
'I learned the hard way,' Fathauer said. 'I blew it. I just can't think about that this week.'
This is Fathauer's fourth appearance in the U.S. Amateur and the first time he's advanced past the first round of match play.
Pan, a teen from Taiwan, beat Ji Moon 1-up in the morning, then came back to defeat Derek Ernst 5 and 4 in the third round.
Pan will meet Venezuela's Vegas, who advanced with a 6-and-4 win over Kyle Dickey in the third round. Vegas defeated Jon Curran 7 and 5 in the second round.
Knost, the 2007 Amateur Public Links champion, is trying to become just the sixth golfer in history to win two USGA championships in the same year. He had to hold on to beat 54-year-old George Zahringer. Knost was leading 3-up with four holes to go after both golfers eagled the 417-yard, par 4 14th, but Zahringer birdied No. 15 and Knost bogeyed No. 16 to see his lead drop to 1-up heading to No. 17 before holding on for a 2-and-1 win.
'I was leading the whole way and then he made a few birdies,' Knost said. 'Kinda scared me a little bit.'