CHICAGO • Jason Day rolled in a 43-foot eagle putt at the 18th hole on Friday to equal the lowest 36-hole total in PGA Tour history and seize a five-shot lead in the BMW Championship.
The red-hot Australian golfer, who finished off a first-round 61 on Friday morning, signed for an eight-under-par 63 for the second round at Conway Farms for an 18-under total of 124.
That put him five in front of US tour rookie Daniel Berger (64) and Brendon Todd (63).
"I don't know how else to explain the way I've been playing," Day said.
"I feel very free, like there's no stress. There's obviously stress but I'm enjoying it."
He also had a leg up on world No. 2 Jordan Spieth and No. 1 Rory McIlroy. And the third-ranked Australian could leapfrog to the summit of the world rankings with a victory on Sunday.
Spieth, who played alongside Day in the first two rounds, fired a second-round 66 for a share of fourth on 132, alongside fellow American Kevin Na (66).
McIlroy fired a 65 to head a group sharing ninth on 133.
Day, whose four victories this season include his first Major title at the PGA Championship last month, had seven birdies and one bogey to go with his eagle in the second round.
His 124 matched the record 36-hole total set by Pat Perez in 2009 and equalled by David Toms in 2011.
Spieth, who also eagled the final hole to stay within striking distance, said Day had been so impressive in the two rounds they played together that it would have been worth the price of an admission ticket to watch.
"I feel like I should be paying to watch this event," he said of the penultimate leg of the FedExCup.
Their day started when they returned to their final first-round hole, the par-four ninth, where Day needed to hole his second shot to make the magical 59.
His 45-yard pitch shot from rain-soaked rough did not make it.
He settled for a par that still gave him a career-best round of 61.
The 27-year-old had opened the FedExCup play-offs by winning the Barclays on Aug 30 and tops the standings.
The play-off race will be capped by next week's Tour Championship where a US$10 million (S$14 million) bonus will be on offer to the series winner.
Day 4: StarHub Ch204, midnight