Cameron Smith's $20 million blunder in latest golfing meltdown

Aussie golfer Cameron Smith has fallen agonisingly short of victory in the US PGA Tour's opening FedExCup play-off event, losing a sudden-death playoff at the Northern Trust.

After posting a spectacular course-record 60 on Saturday, Smith was the joint leader with World No.1 John Rahm after 54 holes.

'BLEW IT': Adam Scott's horror putt costs him $1 million

WOW: Pro golfer's all-time horror show in ugly 38-year first

Smith then closed with a four-under 67 on Sunday, finishing equal-leader at 20-under after Tony Finau recorded a final-round-low 65.

But the Aussie star gifted victory to Finau when he drove out of bounds on the first playoff hole.

Without a win since the 2016 Puerto Rico Open, Finau has been knocking on the door relentlessly for another breakthrough.

The 31-year-old has posted 11 top-3 finishes since and 39 top-10s, including five in his past eight majors.

Finau had also lost three tournaments in playoffs.

As well as the spoils, Finau rocketed into the lead of the overall FexExCup standings and into poll position for a mega $US15 million ($A21m) bonus pay day at season's end.

Smith has soared from 16th to third in the standings before the second play-offs event, the BMW Championship in Maryland starting on Thursday.

Fellow Australians Marc Leishman, Cam Davis and Matt Jones also progressed after maintaining their positions in the top 70.

But the season is over for former World No.1s Jason Day and Adam Scott after they missed the cut in New Jersey.

Cameron Smith's latest late-tournament meltdown

It was more heartache for Smith after he also fell agonisingly short at the World Golf Championships-FedEx St Jude Invitational, costing himself a $2 million payday.

Smith was tied for the lead at 16-under heading into the final hole earlier this month, but finished two shots out of a three-man playoff after going for an all-or-nothing play.

A week after falling short of a bronze-medal playoff at the Olympics with a bogey on his 72nd hole in Tokyo, Smith could have joined Abraham Ancer, Hideki Matsuyama and Sam Burns in the TPC Southwind playoff.

But Smith tried to win the tournament before the playoff and it backfired.

On the 18th hole, the Aussie ended up behind trees that were blocking his way to the green after he sliced his tee shot well right.

Despite seemingly having no option but to bail out and try and get up and down for par from the fairway - which he achieved with his second ball - Smith elected to fire at the green from a dusty lie.

Hit shot cannoned off a tree and out of bounds.

Smith ended up finishing tied for fifth and won $520,000, a little less than the nearly $2.5 million for the winner.

with AAP

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.