Aussie golfer Jason Day is now officially our country's best male golfer after being ranked No.19 in the world.

Day finished fifth when defending his title at the Byron Nelson Championship in Dallas, Texas, last weekend.

It was his sixth top-10 finish so far this season and his best ranking to date.

Fellow Australian golfer Scott Day slipped to No.23.

Geoff Ogilvy is now ranked 31 and Robert Allenby 37.

Day will not be competing in this weeks' USA PGA Tour event as he wanted to focus on this month's US Open.