Norton - Australia's Jason Day fired a three-under par 68 to match American Ryan Palmer for the lead after Saturday's second round of the PGA Tour's Deutsche Bank Championship.
Day and Palmer, who fired a par 71, stood on eight-under par 134 after 36 holes with Americans Matt Kuchar and Billy Horschel on 135 and Americans Bill Haas, Patrick Reed, Webb Simpson, Russell Henley and Keegan Bradley on 136.
Only the 70 points leaders after this week's second event of the US tour's season-ending playoffs with advance to next week's BMW Championship in Denver, which will decide the 30 qualifiers for the Tour Championship in two weeks.
Day sizzled at the start with five birdie putts on the front nine, the longest a 40-footer at the par-4 sixth. He also dropped a pair of six-foot birdies at the fourth and ninth and 15-footers at the par-5 second and seventh holes.
But Day took a bogey at 12 after a penalty drop and another at 14 after finishing a greenside bunker. He sank a seven-foot birdie putt at the par-3 16th to grab the lead alone but took a bogey at the par-5 18th, missing a six-foot par putt on the second-easiest-playing hole on the course.
"It's not playing easy," Day said. "I made it look easy on the front nine, rolled in a lot of good birdie chances.
"On the back nine I just made a few errors. I got off to a cracking start and came home a little rough. But I'm confident heading into tomorrow."
Day seeks his first PGA victory after sharing or leading after 36 holes.
"Very encouraged," Day said. "Overall I'm very happy with how I'm playing.
"I've got to keep my head down, stay aggressive and hopefully I win this one."
Palmer endured a roller-coaster round that began with a birdie followed by a double bogey at the second and a bogey at the par-3 third. He followed with back-to-back birdies at four and five but stumbled with a bogey at the par-3 eighth.
Palmer began the back nine with a bogey but answered with a 19-foot birdie putt at 12 and a closing birdie after putting his approach inches from the cup.
Kuchar began on the back nine and fired six birdies in a row for the first time in a PGA event, making nine in all on his way to a 66.
After two birdies and two bogeys in his first six holes, Kuchar began his birdie run at 17 and moved into contention before stumbling late with bogeys at seven and nine around a birdie at eight.
"It was a good stretch," Kucher said. "A lot of those are birdie holes. That stretch is one you would hope to take advantage of."
Kuchar has been playing with a heavy heart in the wake of the unexpected death of his caddie Lance Bennett's wife, Angela, on Wednesday after suffering a seizure.
"Today was easier," he said. "Still felt like Angela was on my mind almost every hole, every shot. But yesterday I had a hard time following through a couple of times."
Bennett was not at the event, staying at home in Dallas making plans for Tuesday's funeral even as Kuchar felt something special around his game.
"I certainly feel like there's some fate working, balls going in, balls to stay where they should," Kuchar said. "I hope there's some inspiration and some fate working for me out here."
Haas figures he needs a win or a runner-up effort to gain a Ryder Cup captain's pick.
"I didn't put myself in position to be a lock or anything like that," Haas said. "So I'm just going out and trying to play my best."Leading scores on Saturday from the second round of the US PGA Deutsche Bank Championship (par-71, USA unless noted):
134 - Ryan Palmer 63-71, Jason Day (AUS) 66-68
135 - Matt Kuchar 69-66, Billy Horschel 69-66
136 - Bill Haas 67-69, Russell Henley 70-66, Patrick Reed 68-68, Keegan Bradley 65-71, Webb Simpson 66-70
137 - Russell Knox (SCO) 67-70, Noh Seung-Yul (KOR) 69-68, Jordan Spieth 67-70, Martin Kaymer (GER) 71-66, Ben Crane 69-68
138 - Chris Stroud 69-69, Jim Furyk 72-66
- Rickie Fowler 70-69, Zach Johnson 71-68, Chesson Hadley 66-73, Danny
Lee (NZL) 74-65, Chris Kirk 73-66, Rory McIlroy (NIR) 70-69
Kevin Streelman 73-67, Gonzalo Fernandez-Castano (ESP) 71-69, Vijay
Singh (FIJ) 72-68, Robert Streb 73-67, Henrik Stenson (SWE) 70-70, John
Senden (AUS) 69-71, Jimmy Walker 70-70, Jason Kokrak 68-72, Carl
Pettersson (SWE) 67-73, Ian Poulter (ENG) 67-73