In the history of the the PGA Tour Champions, the 72-hole scoring record belongs to one player -- the only player to break 260 for four rounds in an event.
Most PGA Tour Champions events -- except for the majors and the Charles Schwab Cup playoffs -- are 54 holes. However, on the rare occasion the 50-plus senior circuit plays four rounds, the guys still take it deep. Tom Lehman holds the 72-hole scoring record on PGA Tour Champions, shooting 22-under 258 to win the 2012 Charles Schwab Cup Championship.
Kenny Perry and Jack Nicklaus own the 72-hole scoring record in a PGA Tour Champions major, both setting the mark in the Senior Players Championship. Jack Nicklaus shot 27-under 261 in 1990, and Perry shot 19-under 261 to win the 2013 edition of the event. To this day, Nicklaus' 27-under score is by far the lowest against par in a 72-hole event.
In the normal 54-hole PGA Tour Champions events, the lowest score is 191, shot five times in PGA Tour Champions history -- most recently by Rocco Mediate to win the 2013 Shaw Charity Classic in Canada. In 72-hole events, the lowest first 54 holes is 192, shot by Steve Stricker in the first three rounds of the 2019 US Senior Open at Warren Golf Course at the University of Notre Dame in Indiana.
Most golf fans also know the lowest 18-hole score ever recorded on PGA Tour Champions is 59. Kevin Sutherland is the only player to break 60 on PGA Tour Champions, shooting 13-under 59 in the second round of the 2014 Dick's Sporting Goods Open at En-Joie Golf Club in New York.
The other significant scoring records in PGA Tour Champions, the 36-hole scoring record, was set by Bruce Fleisher when he shot 16-under 124 in the first two rounds of the 2002 RJR Championship.