A blistering front nine from Kenny Perry helped the veteran American surge into the lead at the Tour Championship as overnight leader Tiger Woods hit a roadblock in Georgia.
With play brought forward by more than three hours in a bid to beat heavy rain forecast later in the day, 49-year-old Perry also opened his third round at East Lake in a hurry.
Perry sank birdies on the first four holes at the PGA Tour’s FedEx Cup finale.
Perry had started the day at two under par, three shots behind Woods, and though a bogey at the par-three sixth checked his progress, he rebounded with another birdie at the seventh to make the turn in 31.
That gave him a share of the lead with Woods and Ireland’s Padraig Harrington, who were experiencing rollercoaster rounds early in their day.
FedEx Cup standings leader Woods began with a one-shot lead over Harrington and first-round leader Sean O’Hair.
Paired once more with the Irish three-time major winner, Woods saw his lead disappear at the first hole as Harrington birdied, but then edged back in front with a birdie of his own at the par-three second.
The nip and tuck continued as Harrington birdied the third, only to post back-to-back bogey fives at the fourth and fifth.
Then Woods wobbled, bogeying the seventh and 10th as Harrington birdied the eighth, but the world number one – knowing a victory on Sunday would guarantee him the FedEx Cup title and a $10m (€6.8m) bonus – got back to level for the day and five under for the tournament with a birdie at the 11th.
Their private duel was being eclipsed, however, as Perry birdied the 12th and 15th to move into a three-shot lead over Woods and O’Hair at eight under par, with Harrington falling back into a tie for third at four under following a bogey at the 12th.
O’Hair had played 13 holes while also on four under was world number three Phil Mickelson, who continued to rebound from an opening 73.
Mickelson had got back into contention on Friday with a 67 and his good form extended into Saturday with a 66.
South Africa’s Ernie Els had started the day in fourth place at three under but fell off the pace with two early bogeys. He rallied on the back nine with birdies at the 12th and 14th and was back to three under with four to play.
England’s Luke Donald had a bad day at East Lake, an eight-over-par 78 sending him tumbling down the leaderboard to 29th place at nine over, while Australia’s Geoff Ogilvy moved in the other direction, climbing from last place in the 30-man field to a tie for 17th with a 64.