REUTERS: Marc Leishman continued his strong form, carding nine-under-par 62 for the first-round lead at the BMW Championship outside Chicago on Thursday.
The Australian holed 10 birdies for a three-shot clubhouse advantage over Americans Jordan Spieth and Keegan Bradley at Conway Farms in Lake Forest.
Spieth heads the FedExCup standings - and the race for the US$10 million (7.46 million pounds) bonus awarded to the overall season champion - with only next week's Tour Championship left after this week.
Leishman, seventh in the standings, is coming off a third place finish in the previous event in the tour's playoff series.
"I hit the ball well and (the) putter co-operated again. It's nice when you get on a run like this," Leishman told Golf Channel.
Only two of his birdies came from outside 12 feet.
The 33-year-old has won twice in 222 starts on tour, including the Arnold Palmer Invitational in March, and is gearing up for his third Presidents Cup appearance for the International team in two weeks.
Spieth, meanwhile, survived a tardy start to move up the leaderboard.
"Bogey-free was really solid today, considering some of the spots I hit it," he said.
"Good putting early. I only hit one of my first five greens and was (two-under). I feel I stole a couple there."
Spieth's closest pursuer in the FedExCup standings, compatriot Justin Thomas, started well with a four-under 67.
It was also a good day for veteran Phil Mickelson, who shot 66.
"I've been able to go the whole round with much better focus, much better energy," the American said.
"I got away with one or two bad swings and then hit it well the rest of the day."
Seventy players are contesting this week's event, with only 30 advancing to the season finale next week in Atlanta, Georgia.
(Reporting by Andrew Both in Cary, North Carolina; Editing by Christian Radnedge)