Australians Cameron Smith and Marc Leishman had quiet but lucrative days at the Tour Championship in Atlanta today as world No. 1 Dustin Johnson cruised to an anti-climactic three-shot victory.

Johnson, who started the week with a two-shot lead owing to the tour’s handicap system, was rarely threatened in picking up the Fedex Cup and $US 15 million as the season’s best player.

Smith shot a one-over par 71 that included a double bogey on the first hole, finished tied-24th in the 30-man field but collected $US 445,000 for his troubles.

Leishman closed with a one-under par 69 and finished 29th, earning $US405,000.

Neither threatened to contend in the tournament but under the system – Smith started 10 back from Johnson and Leishman nine back – this was not unexpected.

They will dust themselves off now to play out the rest of a year that includes two majors – the US Open at Winged Foot and the Masters.

Johnson shot a 68 that left him 21-under par, which was enough.

His lead was trimmed to two shots on the back nine with Justin Thomas threatening and Xander Schaffele charging, but Johnson fist-pumped when he holed a six-metre birdie on the 13th that took the wolves from his door.

“This is a tough golf course. No lead is safe,” Johnson said. “The guys gave me a good fight today.”

Schauffele (65 today) had the lowest score of the week at 15-under, earning $US4.5 million along with Thomas in a tie for second.

“I controlled my own destiny, but I still had to go out and play well,’’ said Johnson. “I had a lot of great players right behind me. It got close at the end. I knew it was going to come down the stretch and I'd have to hit some golf shots.”

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