World number one Luke Donald shot his best opening round of the year on the PGA Tour to lie one shot off the lead at the Deutsche Bank Championship FedEx Cup play-off in Boston.
The 33-year-old fired six birdies and a solitary bogey for a five-under-par 66.
Troy Matteson of the United States holds the early lead after a sparkling round of 65.
England's Justin Rose is five off the lead with Northern Irishman Graeme McDowell one shot further back.
The Deutsche Bank Championship is the second leg of the four-event FedEx Cup series, a competition in which Donald, who currently tops the world rankings and both the US and European Tour money lists, currently lies fifth.
The Englishman made a flying start, picking up a birdie at the first before bogeying the second - the only blemish on his scorecard.
Five birdies in the next nine holes followed before he completed his round with seven straight pars.
It was a turnaround in form for Donald who has struggled to make an impact in any of this year's four majors despite his lofty world ranking.
But the form and consistency which has seen him notch up 10 top-10 finishes on the PGA Tour, including victory at the WGC-Accenture Match Play in February, showed glimpses of a return at TPC Boston.
Donald said: "Sometimes I've not played that great in the first round and I've been playing catch-up so it's nice to post five under. I'm in a great position.
"The last month or so I haven't short-gamed it well enough - I haven't made those putts when I needed to. Today I did.
"That was really the difference between five under and maybe two under and being back in the pack.
"It's nice to see the putter warming up a little bit.
"There's a little bit more urgency to do well and win because it is the play-offs and with the points being so much more there's a lot of value in winning.
"Winning goes a long way - it'll set you up great for the Tour Championship and that's always the goal this week."