Four players were tied on 17 under midway through the final round as the PGA Tour BMW Championship drew to an exciting conclusion at Crooked Stick in Carmel, Indiana.
US pair Dustin Johnson and Phil Mickelson sat alongside England's Lee Westwood and USPGA champion Rory McIlroy, while Vijay Singh was also waiting in the wings with just a single shot covering the top five players.
Mickelson, who shared the overnight lead with Fijian Singh, sank birdies on the second and fifth holes to move one shot ahead but then had a bogey on the seventh and was back among the pack after eight holes.
The four-time major winner had produced the performance of the day yesterday, equalling the course record with a stunning eight-under-par 64 to move to 16 under alongside Singh.
Johnson was building a superb fourth round with birdies at the first and eighth holes followed by an eagle on the par-five ninth and was three under for the day at the halfway mark.
Westwood was two under through eight holes, picking up shots at the second, fifth and eighth while bogeying the third.
McIlroy was also two under after eight holes having carded birdies at the second and fifth holes.
Singh picked up a shot at the fifth but then dropped it again two holes later to remain on 16 under, one behind the top four.
Australia's Adam Scott was a shot further back on 15 under after nine holes, following an eventful round so far of four birdies and three bogeys.
Tiger Woods was among a group of five players tied on 14 under, with the American one under through nine.