Jeff Quinney increased his chances for a repeat, as the 22-year-old beat U.S. Walker Cup teammate D.J. Trahan 1-up to move into the afternoon set of matches, while James Driscoll handed Casey Yates a 6-and-5 routing.
'It was a combination of him not playing as well as he has been and I played pretty well,' said Driscoll, who finished second to Quinney in last year's final match.
Both players now advance into Thursday afternoon's third round.
Quinney will square off against Kris Mikkelson, while Driscoll is scheduled to play Taichiro Kiyoto of Japan.
Results of Thursdays second round of match play:
Robert Hamilton def. Greg Earnhardt - 3 and 2.
Daniel Ozley def. Scott Abbott - 20 holes.
Daniel Summerhays def. Brooks Kelly - 2 and 1.
Billy Harvey def. Jerry Courville - 2 and 1.
James Driscoll def. Casey Yates, Fouke, Ariz. (142) - 6 and 5.
Taichiro Kiyota def. Sandy Horacek - 2 and 1
Nick Watney def. Nicholas Thompson - 7 and 6.
Manuel Merizalde def. Nick Cassini - 5 and 4.
Brian Nosler def. Robert Godfrey - 2 and 1.
Michael Webb def. Jamie Elson - 3 and 2.
Kris Mikkelsen def. John Engler - 1 up.
Jeff Quinney def. D.J. Trahan - 1 up.
Michael Sims def. Simon Nash - 1 up.
John Carlson def. Ryan Blaum - 1 up
Camilo Villegas def. Andy Doeden - 1 up
Bubba Dickerson def. Chris Nalen - 1 up
Afternoon Matches - Schedule
1:30 p.m. ' Hamilton vs. Ozley
1:40 p.m. ' Summerhays vs. Harvey
1:50 p.m. ' Driscoll vs. Kiyota
2:00 p.m. ' Watney vs. Merizalde
2:10 p.m. ' Nosler vs. Webb
2:20 p.m. ' Mikkelson vs. Quinney
2:30 p.m. ' Sims vs. Carlson
2:40 p.m. ' Villegas vs. Dickerson