Illinois - Jason Day missed a shot at carding the seventh 59 in PGA Tour history but still enjoyed a career-best round to grab a four-shot lead after the weather-delayed opening round of the BMW Championship on Friday.
Day, seeking a fourth win in six starts, returned to Conway Farms Golf Club after overnight thunderstorms with a 44-yard chip shot from deep rough standing between him and a magical 59.
But his attempt was short by nine feet and he failed to make the birdie putt, leaving the 27-year-old Australian with an opening 61 in the third of the PGA Tour's four concluding playoff events in the season-long FedExCup race.
"Selfishly, a 59 would have been great and only a handful of guys have shot 59, and I understand what the history is, but right now winning the tournament is more important than shooting the 59," said Day, who could reach the top of the world rankings with victory this week.
"Overall I hit a pretty good chip, but I thought it was just going to bounce a little bit more than what it did."
Masters and U.S. Open champion Jordan Spieth, playing with Day, was in a six-way share of second place at six under along with fellow Americans Bubba Watson, Justin Thomas, Daniel Berger, Kevin Na, and Harris English.
World number one Rory McIlroy (68) was seven shots back.
61 - Jason Day (AUS)
65 - Kevin Na, Daniel Berger, Justin Thomas, Jordan Spieth, Bubba Watson, Harris English
66 - Brendon Todd, Kevin Chappell, Brian Harman
67 - Paul Casey (ENG), Matt Kuchar, George McNeill, Scott Piercy, Ryan Palmer, Brendon de Jonge (ZIM), Danny Lee (NZL)
68 - Bill Haas, Rory McIlroy (NIR), Hunter Mahan, Sean O'Hair, Patrick Reed, Zach Johnson, Brendan Steele, Phil Mickelson, Keegan Bradley, Nick Watney