New World No. 2 Dustin Johnson has made it back-to-back victories capturing the WGC – Bridgestone Invitational thanks to a final round flop from World No. 1 Jason Day.

Johnson, and the reigning US Open champion, posted a weekend pair of 66s that handed him victory on the tough tree-lined Firestone CC course in suburban Akron, Ohio.

And unlike the scenario that unfolded over the closing eight holes at Oakmont, Johnson was fully aware of his score.

Victory has now put Johnson into clear favouritism to win a second straight Major when he tees up next week in the 145th Open Championship at Royal Troon in Scotland.

And given the manner Johnson handled last month’s USGA debacle at Oakmont to capture a first Major, then a second could be just 14 days away along the shoreline of the Irish Sea.

Day, who lives in nearby Cleveland, Ohio, went into the last round tied for the lead with American Scott Piercy but clearly fighting with his swing as evident during day three.

“I am not sure where ball is going,” he said post the third round.

And while the Australian eagled the second the writing was clearly on the wall as Day continued to struggle finding fairways.

Sadly, Day’s effort over the closing 18 holes included ending his round with a 15th hole bogey and then 16th hole double bogey when he was forced to chip out from trees down the right side only to find a green side water hazard, along with a par at 17 and then a further dropped shot at 18 in a round of a two over 72 and an eventual share of third place on three under par.

It is the first occasion in six tournaments Day has led after 54 holes and going to the final 18 he has failed to capture victory.

Double Major winning Jordan Spieth, who is now back to No. 3 in the world, closed with a 67 and tied for third with compatriots Matt Kuchar (66), Kevin Chappell (67) and the crestfallen Day.

Victory is Johnson’s third WGC title after capturing the 2013 WGC – HSBC Champions in Shanghai and last year’s 2015 WGC – Cadillac Championship at Doral in Miami.

Johnson had spent last week in The Bahamas when he celebrated his 32nd birthday and a long overdue first Major.

However he was still three shots behind on the last day when he rolled in a 15-foot birdie putt on the 13th hole, and followed with a wedge into 8 feet for birdie on the next hole, and about the same time Day was finding huge trouble down the right of the 16th, Johnson blasted a 9-iron out of the thick rough on the 17th to 15 feet and rolled in the birdie putt to take command.

The Myrtle Beach based Johnson now has 11 career victories in his nine years on the PGA Tour.

“I feel great,” he said. “I feel like my game is where it has been all year. I just haven’t been putting quite as well as I’d like. The last couple of weeks, I just putted a little better.

“And I didn’t know my score until I was 18 when my brother, and also my caddy, mentioned to me that Jason had gone into the water at 16 so I knew my score then but also by then it didn’t really matter.”

He made it sound so simple, even as the back nine became so complicated.

Johnson’s only real trouble was down the last when he pulled his tee shot left into the rough and playing his second, he clipped a dead branch with his punch shot, and with his ball finding deeper rough.

But instead of trying to play over a bunker, he pitched to the far collar of the green and lagged his putt to make sure he made nothing worse than bogey.