Edison - PGA Championship winner Jason Day and Bae Sang-Moon jumped on the birdie bandwagon on Saturday, both firing seven-under-par 63 to share the 54-hole lead at the Barclays.
Australia's Day, who captured his first major title at Whistling Straits two weeks ago, had six birdies and an eagle with just one bogey as he joined playing partner Bae on 11-under-par 199 at Plainfield Country Club.
Bae, who birdied four of his first seven holes, finished with nine birdies and two bogeys for his share of a one-stroke lead over two-time Masters champion Bubba Watson.
Watson, who held a one-stroke overnight lead, carded a three-under-par 67 for 200, giving him sole possession of third place, one stroke in front of British Open champion Zach Johnson (67), Sweden's Henrik Stenson (67) and Ryan Palmer (65).
Day said Bae's hot start - with birdies at the first, third, fifth and seventh, helped him get going, too.
"It was a good day," he said. "To be able to have Sang-Moon get off to a good start, he hit it great all day. We're kind of feeding off each other, drafting off each other there today."
Day said he knew that good scores were to be had after Mexico's Carlos Ortiz went out early and posted an eight-under-par 62 and England's Justin Rose fired a 63.
The 27-year-old Aussie, who started the tournament battling nagging back trouble, rolled in a 17-footer for eagle at the 16th and after promptly giving a stroke back with a bogey at 17, birdied the last.
"There's still 18 holes to go," Day said. "It's going to be very difficult tomorrow.
"I've just got to keep pushing, because the moment that you're satisfied with a score is the moment that you mentally kind of take a break and you start making mistakes."
Bae ended a run of three straight birdies at 14, 15, 16 with a bogey of his own at 17, but like Day he capped his round with a birdie.
"I made a lot of birdie putts," said Bae, who is trying to play well enough to get the nod for the International team for the Presidents Cup, which will be played in South Korea in October. "The putter worked really good today. I had a really, really solid round."
Bae, who last month lost his bid to have his mandatory two-year military service in South Korea deferred, said he preferred to keep his mind on golf this week, rather than the approaching start of that service.
"I have to go back. So that is a few weeks later," Bae said. "So I just want to play good golf this week and really want to play Presidents Cup in my country."
A win this week would put Bae in the top 10 in the Presidents Cup standings and secure his spot on the International team.
A solid performance might still earn him selection by International captain Nick Price.
Leading third-round scores on Friday in the $8.25 million Barclays,
first event in the PGA Tour playoffs (par 70, USA unless noted):
199 - Bae Sang-Moon (KOR) 69-67-63, Jason Day (AUS) 68-68-63
200 - Bubba Watson 65-68-67
201 - Ryan Palmer 69-67-65, Zach Johnson 69-65-67, Henrik Stenson (SWE) 68-66-67
203 - Carlos Ortiz (MEX) 73-68-62, Kevin Kisner 67-71-65, Spencer Levin 65-71-67, Jason Dufner 66-68-69
204 - Zac Blair 69-68-67, Bryce Molder 66-71-67, Russell Knox (SCO) 66-71-67
- Justin Rose (ENG) 77-65-63, Kevin Na 69-69-67, Hideki Matsuyama (JPN)
69-69-67, Daniel Summerhays 67-70-68, Camilo Villegas (COL) 65-70-70,
Tony Finau 65-69-71
206 - Luke Donald (ENG) 73-68-65, Brendon Todd
70-70-66, Jim Furyk 68-69-69, Cameron Tringale 66-71-69, Robert Streb
68-68-70, Sean O'Hair 68-68-70
207 - Matt Kuchar 71-70-66, Stewart
Cink 67-73-67, Dustin Johnson 70-70-67, Jim Herman 69-69-69, Pat Perez
68-69-70, Hudson Swafford 68-68-71, Jason Bohn 71-64-72