After starting the final round at 12 under par with a three shot lead Spieth arrived at the par-3 6th hole having extended his lead by a further two shots over Johnson, who continually burned the edges of the cup with his birdie attempts on the front side.

“Just the front nine, I could not hole a putt,” Johnson said after his round. “I hit really good putts the whole time, just burning the edges all day.”

Spieth found the water with his tee shot at the par-3, eventually holing out for a double bogey five, while Johnson made the sixth of eight straight pars to stay in touch with the 24-year-old.

Jordan Spieth plays from the drop zone after finding the water at the par-3 6th. PHOTO: Chris Condon/Getty Images

The momentum swung Johnson’s way after he finally made his first birdie of the day at the 9th hole and followed it up with another at the next to find himself level with his compatriot in what became a two horse race for the opening FedEx Cup playoff event.

“Finally made my first birdie on 9, and birdied 10. So got back; squared it up through ten holes there. The back nine was a lot of fun. I knew it was going to be tough and come down to the end, and it did,” he said.

After trading blows throughout the back nine the two Americans reached the par-3 17th tied for the lead. Both players found the greenside bunker from the tee and the advantage appeared to be Johnson’s after hitting his bunker shot close. Spieth, however, wasn’t done yet, holing a curling 19 foot par putt to putt the pressure back on the 33-year-old as they headed to the last hole of regulation.

FINAL LEADERBOARD

Johnson’s drive on the 72nd hole found a downslope in the right rough forcing him to lay up and trust his ability to hit a wedge close to the hole rather than attempt the difficult shot required to find the putting surface perched high above the fairway.

“I figure my best bet was, I know I'm swinging really well and hitting my wedges good, you know, to leave myself at a good number, which I did,” the World No.1 said of taking his medicine after finding trouble at the last.

Thinking par would be sufficient Spieth safely found the green in regulation and lagged his birdie putt from over 70-feet close to the hole to secure his four and a 13 under par total. Seeming to put an end to the valiant challenge from Johnson, whose wedge approach had found the back of the green leaving a lightning fast and slippery 18-foot par putt.

Using a new putter he put in play at the start of the week the man known as DJ found the bottom of the cup, despite a near lip out, to sign for a 4 under final round 66 to force a playoff.

Dustin Johnson watches intently as his par putt on 18 finds the hole to force a playoff. PHOTO: Chris Condon/Getty Images

Returning to the 18th tee Johnson took advantage of a change in wind direction, taking an aggressive line over the water to the left leaving a lob wedge approach. While Spieth’s more conservative line with driver left him with a mid-iron to the green.

When asked after the round of what proved to be the defining shot from the tee Johnson was his typical nonchalant self. Describing the impressive display of power and precision under pressure by saying, “It's only 300 carry. I can cover that.”

Spieth again found the green safely but needed to hole his birdie putt from 25-feet after Johnson knocked his approach to within a few feet to almost guarantee a three. Spieth missed while Johnson converted his short birdie chance to claim his fourth victory for the year and 16th on the PGA Tour.

Spieth remained philosophical after the sudden death loss and was full of praise for Johnson who know finds himself atop the FedEx Cup standings with only three events left in the playoff series.

“I didn't lose it ... He won it,” Spieth said.

Jason Day was the highest finisher of the five Australians in the field after coming home with a wet sail on the weekend, with his rounds of 68 and 67 elevating him into a tie for 6th.

Geoff Ogilvy's tie for 40th was the next best of the Australians who made the weekend in New York, but wasnt enough to extend his playoff run, finishing outside the required top 100 on the FedEx Cup standings to earn a place in Boston next week.