By Jeff Haney

Published Sunday, March 8, 2009 | 1:07 p.m.

Updated Sunday, March 8, 2009 | 1:26 p.m.

Huck Seed and Sam Farha won the first two quarterfinal matches Sunday to advance to the final four of the National Heads-Up Poker Championship at Caesars Palace.

Farha defeated David Williams to remain in the running for the $500,000 top prize in the tournament, which concludes Sunday evening. Seed, the only player to have cashed in all five years of the National Heads-Up Poker Championship, ousted David Oppenheim.

Players finishing ninth through 16th earn $25,000; fifth through eighth place pays $75,000; the third- and fourth-place finishers each win $125,000; and the runner-up receives $250,000.

In Saturday's round of 16:

Williams def. Erick Lindgren

Farha def. John Phan

Oppenheim def. Kenny Tran

Seed def. Glen Chorny

Vanessa Rousso def. Paul Wasicka

Daniel Negreanu def. Scotty Nguyen

Bertrand Grospellier def. John Juanda

Phil Hellmuth def. Tom Dwan

In Saturday's round of 32:

Lindgren def. Eli Elezra

Williams def. Scott Fischman

Phan def. Jerry Yang

Farha def. Peter Eastgate

Tran def. Jennifer Harman

Oppenheim def. Phil Laak

Seed def. Gus Hansen

Chorny def. Brad Garrett

Wasicka def. Don Cheadle

Rousso def. Phil Ivey

Nguyen def. Ted Forrest

Negreanu def. Dario Minieri

Juanda def. Gabe Kaplan

Grospellier def. Ilari Sahamies

Hellmuth def. Jeffrey Ishbia

Dwan def. Barry Greenstein