Australian Marc Leishman just shaded playing partner Tiger Woods after their opening two rounds at the PGA Tour's Quicken Loans National.
Leishman carded a second-straight round of three under 67 to be tied for seventh at six under, after four birdies and a bogey on Friday.
Woods wielded his new putter with precision to match his lowest score of the year, a five-under-par 65, to be a shot back of Leishman at five under - in a tie for 11th.
The 14-times major champion Woods set the tone for a storming round when his 25-foot birdie putt on the first hole found the dead centre of the cup on a warm and calm morning at TPC Potomac at Avenel Farm in Maryland.
In the American's 11th tournament of the year on his comeback from spinal fusion surgery, Woods issued what might be construed as his most ominous warning yet.
"As the year's progressed, I think I'm not that far away from putting it together where I can win," he said.
Americans Beau Hossler (66), Ryan Armour (65) and Brian Gay (64) share the lead on nine-under, one stroke ahead of compatriot Billy Horschel (68) and Italy's Francesco Molinari (65).
Cameron Percy was the only other Australian to make the cut after a 68 left him at three under and tied for 28th.
Geoff Ogilvy (75) and Aaron Baddeley (72), both two over, missed out on the weekend by a shot while Matt Jones (74) and Rod Pampling (72) were well off the pace.
After missing the cut at the US Open a fortnight ago, Woods switched to a so-called "mallet" putter this week, which he says allows him to make a nice swing at the ball.
"It's a good feeling for me, just go ahead and trust it's going to swing," the 42-year-old said.
"I don't like blocking putts. I like feeling that toe move and cover that ball and it felt good today."
The solid putting was not confined to just his first hole, the par-five 10th. He also banged in two more birdies from nearly 20 feet before suffering a hiccup at the 17th, where he three-putted.
However, he rebounded by pitching in from 30 yards for birdie at the next, even reading the break perfectly as his ball curled into the cup as the large gallery erupted.