WISCONSIN (AFP) - Australia's Jason Day won the PGA Championship in historic fashion on Sunday, capturing his first grand slam title with a 20-under par total unprecedented in major championship history.

The world No. 5 Day carded a five-under par 67 in the final round at Whistling Straits for a 20-under total of 268 - breaking Tiger Woods's major-record low winning total of 19-under set at the British Open in 2000.

Day, 27, thwarted Masters and US Open champion Jordan Spieth's bid to become the third man to capture a three majors in one year.

But the 22-year-old American had the consolation of seizing the world No. 1 ranking from Rory McIlroy with his runner-up finish after firing a four-under 68 for 17-under 271.

The Northern Irishman, in his first tournament start after injuring his ankle last month, closed with a 69 for a 279 total and was 17th.

Asia's Anirban Lahiri of India signed for a 68 and a 275 total and was tied-fifth with American Brooks Koepka (66).