LOS ANGELES (REUTERS) - Dustin Johnson secured the world No. 1 ranking in style when he smoked the field for a five-stroke victory at the Genesis Open in southern California on Sunday (Feb 19).

With the victory, the American jumps from third to first in the world rankings, supplanting Australian Jason Day.

Johnson started the final round with a five-shot lead and was never headed after birdies at the first two holes en route to a closing 71 on the storied Riviera course.

Despite two late bogeys, he finished at 17-under 267, with Thomas Pieters (63) of Belgium and American Scott Brown (67) a distant second on 12 under in the event formerly named the Los Angeles Open.

Johnson, 32, collects US$1.26 million (S$1.79 million) for his 13th PGA Tour victory. He has won at least once every year since joining the Tour in 2008, the longest active streak.

The reigning US Open champion joins Arnold Palmer, Jack Nicklaus and Tiger Woods in winning every year for at least a decade after starting on the tour.

Palmer and Nicklaus both won their first 17 seasons, while Woods notched 14 straight seasons with a win.

The leaders played 36 holes on Sunday to make up for Friday's near-washout, when the area was lashed by a strong winter storm.