(Getty images)

American Dustin Johnson has become the world's new top ranked male golfer, overtaking Australian, Jason Day.

Johnson ascended to the world No.1 ranking thanks to a five-stroke victory at the Genesis Open at the Riviera Country Club over the weekend.

Day had been world No.1 for the past 47 weeks and 51 weeks overall.

The Aussie finished in a tie for 64th, finishing at two over the tournament.