| Most Under Par Rounds, 4th Round: |
| Score |
Year |
Site |
City |
State |
| 78 |
2007 |
Southern Hills Country Club |
Tulsa |
OK |
| 47 |
2000 |
Valhalla Golf Club |
Louisville |
KY |
| 41 |
1995 |
Riviera Country Club |
Pacific Palisades |
CA |
| 40 |
2011 |
Atlanta Athletic Club |
Atlanta |
GA |
| 37 |
2012 |
Kiawah Island Resort - Ocean Course |
Kiawah Island |
SC |
| 36 |
1996 |
Valhalla Golf Club |
Louisville |
KY |
| 31 |
1984 |
Shoal Creek Country Club |
Birmingham |
AL |
| 30 |
2009 |
Hazeltine National Golf Club |
Chaska |
MN |
| 28 |
2010 |
Whistling Straits |
Kohler |
WI |
| 26 |
1991 |
Crooked Stick Golf Club |
Carmel |
IN |
| 24 |
1985 |
Cherry Hills Country Club |
Englewood |
CO |
| 22 |
2002 |
Hazeltine National Golf Club |
Chaska |
MN |
| 22 |
1967 |
Columbine Country Club |
Denver |
CO |
