The Warrnambool golfer finished the tournament tied for 61st, with a consequent drop from 48th to 57th on the FedEx Cup standings.

It means he will need to produce a strong performance in the next tournament ? the BMW Championship at Cog Hill- later this week to force his way into the top 30.

A top-30 placing would secure a spot in The Tour Championship, the finale of the PGA Tour Playoffs.

Leishman finished tied for second in the BMW Championship last year behind winner Tiger Woods.

The 26-year-old was able to sink six birdies along with a trio of bogeys on the last day of the Deutsche Bank Championship- a contrast to round three when he carded a horror five bogeys and two double bogeys.

His final round 68 added to scores of 71, 68 and 77, his equal-61st finish earning him $US16,125.

Australia's hopefuls had to settle for the minor places as American Charley Hoffman blew away the field at the tournament.

Jason Day and Geoff Ogilvy tied for second with Englishman Luke Donald while Adam Scott was tied fifth and John Senden shared eighth, but nobody had any answer to long-haired Hoffman's brilliance as he came from four back to win by five shots.

The 33-year-old Hoffman, who went into the event ranked 132nd in the world, piled up 11 birdies in a spectacular nine-under-par 62 at the Boston TPC on Monday.

He finished at 22-under 262, clinching his second US PGA Tour victory.

Ogilvy, who played with Hoffman, shot an impressive 66, but it paled in comparison with the winner.

"It was a class act and he never looked like doing anything but winning after about three holes," Ogilvy said of Hoffman.

"It's going to be pretty hard to beat a guy who has 11 birdies. I had the best seat in the house to watch that.

"He hit great shots all day, putted really well and as soon as he got himself in trouble he'd go and hole a bunker shot or something like that."

Overnight leader Day (71) was the most disappointed contender, after bogeying the par-five 18th to fall back into a tie for second.

Nonetheless, he improved to fourth place on the tour's points list, with two of four play-off series events completed.

Scott had a closing 67 to finish on 16-under while John Senden (67) was another two strokes back.