Illinois, September 20

Jason Day stayed on track for his fourth victory in six starts and the world No 1 ranking when he earned a six-stroke lead after the third round at the BMW Championship on Saturday.

The Australian was far from his very best, but a two-under 69 at Conway Farms was enough to increase his lead after he started the day five shots clear. He posted a 20-under 193 total in the third of the PGA Tour’s four FedExCup play-off events.

Americans Scott Piercy (67) and Daniel Berger (70) shared second place at 14-under. World No 3 Day, in posting the largest 54-hole lead on the PGA Tour this year, set himself up to claim the world

No 1 ranking. If he wins, he will overtake Rory McIlroy, who shot 67 to be fourth at 13-under. Day would also be the 19th player to earn top ranking, and the third Australian after Greg Norman and Adam Scott.

“I felt like I shot 80,” Day said. “So to be able to squeak out with a 69 and really feel like I got everything that I possibly could out of today’s round, I think that was the best score I could have shot.”

If Day can convert the lead it will be his fifth win of the year after the Farmers Insurance Open, Canadian Open, PGA Championship (his first major title) and the Barclays, the latter three coming in his last five starts.

He would be the first international player with five wins on the American circuit since Vijay Singh of Fiji won nine times in 2004.