Rory McIlroy catapulted himself into contention at the Deutsche Bank Championship with a flawless seven-under 64 that leaves him just two shots off the lead.
The in-form world number one was in sublime touch and seven birdies in his penultimate round carried him into a tie for third on 10 under overall, with American Russell Henley leading the way.
Having won three of his last four tournaments, at the Open Championship, the WGC-Bridgestone Invitational and the US PGA Championship in recent weeks, McIlroy will now fancy his chances of adding to his haul on Monday in this second of four FedEx Cup play-off events.
Speaking after his round, he said on Sky Sports 4: "I converted some more of the chances that I gave myself today. I was pretty frustrated coming off the golf course in the last couple of days because I felt like I left a lot of shots out there.
"Even today, I felt like I might have left a couple out there, especially on the last. But I'm happy with how I converted those chances and I'm going to need to do the same tomorrow if I'm going to win."
McIlroy made an excellent start with birdies at two and three before driving a 132-yard approach to nine feet at the seventh, with a nerveless putt moving him to three under for his round.
Two more excellent up and downs at the 13th and 15th left him with simple putts, while he was inches away from acing the 16th, consoling himself by tapping in for his seventh birdie of the day.
He passed up a chance to close his round with a flourish after finding the rough with his approach on his final hole, but he saved managed to save par and now sits alongside American Chris Kirk and Australia's Jason Day, who was on 12 under after a birdie at the 13th but back-to-back bogeys dropped him back.
Henley tops the standings following a six-under round that contained seven birdies and just a solitary blemish at the par-four sixth.
The 25-year-old is now finely placed, on 12 under for the tournament, to claim the third PGA Tour title of his career, and the second this year following his success at the Honda Classic in March, when McIlroy was among the runners-up.
Billy Horschel is one shot adrift of his United States compatriot after finishing his round with three successive birdies to card a fine 67.
Scotland's Russell Knox is seven shots off the lead after failing to advance his five-under score for the tournament, Ian Poulter is three shots behind after matching Knox's Sunday score, while fellow Englishman Luke Donald is on four-over after his second successive 74 in Boston.