Johnson powers to World No. 1 with Northern Trust triumph

Dustin Johnson firing an eight-under par final-round 63 to win US PGA Northern Trust by 11 strokes.

NEW YORK (AFP) - Dustin Johnson seized the world number one ranking in emphatic style Sunday, firing an eight-under par final-round 63 to win the US PGA Northern Trust by 11 strokes.

Johnson finished with a 30-under par total of 254 at TPC Boston, with Harris English a distant second on 265 after a closing 69.

Johnson s 22-under third-round total had given him the largest 54-hole lead on tour this season -- five strokes -- and he was quick to build on it on Sunday.

He set the tone with an eight-foot eagle putt at the second, set up by a magnificent seven-iron over the water.

He tapped in for birdie at the fourth and rolled in a four-foot birdie at the fifth.

Birdie putts of 10 and 13 feet at the seventh and eighth saw him make the turn five-under for the day, and he rolled in another four-foot birdie at the 12th.

The only thing that slowed him was a weather delay, the horn sounding just after he teed off on 17.

Johnson returned and birdied the par-five 18th in near darkness and steady rain.

He matched the second-lowest score in relation to par in a 72-hole US PGA Tour event.

Ernie Els holds the record of 31-under shot at Kapalua in 2003, and Jordan Spieth won the 2016 Tournament of Champions with a 30-under total.

His margin of victory was the largest on tour since 2006.

"It is a big margin, and I m definitely really proud of that," Johnson said. "I played really good. I knew I was playing well and I knew the guys were going to shoot low.

"So I was trying to get 30-under -- holed a nice little putt on the last hole to get to 30."

After a tough putting round on Thursday, Johnson put himself on the path to victory with an impressive 11-under 60 on Friday -- when he was 11-under through 11 holes before parring his way to the clubhouse.

Told his 30-under total didn t give him a record, Johnson wasn t bothered.

"That s all right," he said, "next time."

Former US Open champion Johnson toppled Spain s Jon Rahm from the top of the rankings, and will also lead the US tour s FedEx Cup standings going into the second playoff event, the BMW Championship.

"Something that I m very proud of is to be number one in the world, and I d like to stay there for a little while," Johnson said.

"Obviously it s been jumping around a bunch here the last few months, but you know, the last time I was number one I think I stayed there for quite some time, and that s another goal of mine is just to see how long I can stay at number one."

South Africa s Louis Oosthuizen grabbed the final spot in the 70-man BMW field with a birdie at the final hole on Sunday, coming back after the rain delay and capping a two-over 73.

That put him in a tie for 13th, and knocked Doc Redman out of the top 70 in the playoff standings.