Jason Day held off the challenge of Jordan Spieth to claim his maiden major title at the US PGA Championship at Whistling Straits. The Australian finished on twenty-under par, three shots clear of Spieth, who has replaced Rory McIlroy as world number one after finishing outright second in Wisconsin.

Day was rarely troubled during a near-faultless fourth round which included seven birdies, with Masters and US Open champion Spieth unable to keep with the ferocious pace. England's Justin Rose finished tied for third five shots behind, level with Branden Grace after both players briefly flirted with the top of the leaderboard.

Brooks Koepka and Anirban Lahiri tied for fifth on thirteen-under, the latter continuing a stunning week for Asian golf in major competition. South Africa's George Coetzee, Matt Kuchar and first round leader Dustin Johnson finished a further shot back in another thrilling climax to a major in 2015.

But even a compelling battle to win the 97th PGA Championship could not distract from the individual performance of Day, who exercised the demons from previous near-misses at numerous major championships to claim a belated victory. Six times the 27-year-old has finished inside the top four in the majors, twice as a runner-up, but never got over the line.

The champion at the Franklin Templeton Shootout led by two-shots after round three, with Spieth ready to pounce on any mistakes. However, Day was nerveless in his approach and though Rose and Grace both led early charges one dropped shot in his first 14 holes cemented his place at the top of the leaderboard.

The Queensland-born player had the luxury of going down the 18th three shots ahead of playing partner Spieth and could therefore ease his way to the title, a victory which will be received among his peers. Meanwhile, with McIlroy finishing in 17th a second place finish for Spieth is enough to see him replace the Northern Irishman at the top of the world rankings after contesting at all three majors.