BMW Championship leader Marc Leishman says he'll head into day two with confidence levels sky-high after bagging his lowest round of the year in Chicago.
Leishman spearheaded a red-hot Australian contingent at Conway Farms Golf Club with countrymen Jason Day and Cameron Smith also high on the leaderboard at the 70-man event.
Fresh from a third-place finish at the previous FedEx Cup play-offs event in Boston, Leishman holds a two-shot lead over world No.9 Day and Americans Charley Hoffman and Jamie Lovemark.
Leishman fired a stunning nine-under-par 62, with Day, Lovemark and Hoffman (all 64) at seven-under.
FedEx Cup points leader Jordan Spieth and Rickie Fowler (both 65) headline a five-way tie for fifth at six-under.
Leishman's 62 is his lowest score during a breakout 2017 season that includes a win at the Arnold Palmer Invitational in March, as well as six top-10s and 14 top-25s.
"A round like that is special. I haven't had a real low round for a long time, so it was nice to do that in a big tournament like the BMW," Leishman said.
At seventh in the FedEx standings, Leishman needs a solo second-place at the BMW to move into the top-five seedings for next week's Tour Championship.
The top-five are guaranteed the $US10 million FedEx cup prize with a victory at East Lake Golf Club in Atlanta.
Leishman hit 16 of 18 greens in regulation and missed just three fairways, while ranking second in the field on the greens.
"I did a lot of work charting and studying the greens before the tournament, like I did in Boston. I'm feeling great with the putter," said Leishman.
Day was enjoying his first round with close mate Luke Reardon as caddie after replacing long-time bagman Colin Swatton. The 2015 BMW winner rattled off an eagle, six birdies, and a bogey to get the new partnership humming.
"Seven under is a great start. I think Luke did a fantastic job out there. We worked well together and hopefully we can keep that going," said Day.
Next best of the Australians was Smith, who fired a 66 to share 10th at five- under with three others including five-time major winner Phil Mickelson.
After missing the cut in the first two play-offs events, Smith admitted he "took the foot off the gas" after starting the post-season guaranteed of making the BMW.
Needing a fourth-placed finish to progress to the 30-man Tour Championship, Smith knows it's do-or-die.
"I could have mailed it in, but I went out there with a slightly different mindset.
"I probably took the foot off the gas in the first two events but this is a big week and I'm up for it."
MARC Leishman is in sizzling form in the US, carding nine under in the first round of the BMW Championship.
He is three shots in front of Jordan Spieth and Keegan Bradley at the competition outside Chicago.
Leishman is placed seventh in the overall standings.
He holed 10 birdies in the race for the $10 million bonus for the overall season champion.
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