Tiger Woods fired his lowest round of the year, a five-under par 66, in Sunday's final round of the Northern Trust, but has work to reach the season-ending Tour Championship.
The reigning Masters champion opened with four consecutive birdies at TPC Boston and parred the back nine on his way to finishing 72 holes on six-under 278 in the US PGA playoff opener.
Woods was outside the top 50 with leaders still waiting to tee off as he finished the round and looked toward next week's BMW Championship.
The 15-time major winner was projected at 56th on the FedEx Cup season points list with 70 advancing to next week but only 30 moving on from the BMW to next month's season finale at East Lake in Atlanta.
Woods had not fired a 66 since the second round of his Hero World Challenge invitational last December.
The 44-year-old American had not gone lower since back-to-back 64s to begin last November's Zozo Championship in Japan, which he won for his 82nd US PGA career title to match Sam Snead's all-time record.
Woods, ranked 16th, had three tap-in birdies on the first four holes and holed a monster 45-foot birdie putt at the par-3 third. He sank a testy nine-footer for par at the fifth then blasted out of a greenside bunker and sank a five-foot birdie putt at the par-5 seventh.
The lone bogey for Woods came at the par-3 eighth after missing the green but he answered with a birdie at the ninth from three feet. He didn't have a par putt beyond six feet on the back nine.