63s shot at the U.S. Open
Player Year Course Round Relation to par
Johnny Miller 1973 Oakmont Fourth 8 under
Jack Nicklaus 1980 Baltusrol First 7 under
Tom Weiskopf 1980 Baltusrol First 7 under
Vijay Singh 2003 Olympia Fields Second 7 under
Justin Thomas 2017 Erin Hills Third 9 under
Seven other players have shot a round of 9 under in a major, the most recent being Hiroshi Iwata in 2015 in the second round of the PGA Championship at Whistling Straits. Thomas is the first to do it in a U.S. Open.