Australian Jason Day replaces Rory McIlroy as world number one

Australian golfer Jason Day has overtaken Rory McIlroy to become number one in the world rankings.

The 27-year-old secured his spot at the top of the pile by winning the BMW Championship by six shots in Chicago, Illinois over the weekend.

Day finished 22-under par for the tournament, while McIlroy's campaign ended in a three-way tie for fourth on 14-under.

"To be honest I had terrible sleep over the last few nights," BBC Sport quotes Day as saying. "Thinking about getting to number one, thinking about winning this tournament, thinking what I had to do to win this tournament to get to number one."

The victory represents Day's seventh PGA Tour title triumph.