Story highlights
Jason Day wins BMW Championship
Fifth victory of the season for Australian
Goes top of golf's world rankings
Daniel Berger finishes second in Illinois
Golf has a new world number one as Jason Day took over at the top from Rory McIlroy with a six-shot victory at the BMW Championship.
The 27-year-old Australian kept his nerve on the final day to card a 69 to finish on 22-under 262 at Conway Farms GC in Illinois with Daniel Berger in second place.
McIlroy, who was sidelined by an ankle injury earlier this season, battled to a 70 to finish tied for fourth, but was never in a position to deny Day his new status.
It is his fifth victory of the PGA Tour season and his fourth in his last six tournaments. including the the final major of the season, the PGA Championship.
Day’s sensational run of form has seen him move clear of McIlroy and American Jordan Spieth, who won the opening two majors of the season and challenged strongly in the other two.
He had started the fourth round with a six-shot advantage, but was unable to pull further clear after a succession of regulation pars.
It was broken with a birdie on the eighth, but he dropped a shot immediately at the next. Birdies on the 16th and 18th sealed his victory after Berger got to within four shots.
It has been a remarkable year for Day, who had threatened for some time to make a major breakthrough.
He led the U.S. Open at Chambers Bay only to suffer a recurrence of a vertigo problem, bravely battling on to finish behind Spieth.
But stunning play in the latter part of the season, including a record 20-under par tally in winning the PGA title at Whistling Straits has seen him amply rewarded.
Day is the 19th player to earn the top spot since the rankings were introduced and the third Australian after Greg Norman and Adam Scott.