Boston - Kevin Chappell, who is hoping to end a string of bridesmaid finishes this season and claim his first PGA Tour title, has a one-shot lead after 36 holes of the Deutsche Bank Championship.
The 30-year-old American took the solo lead with a birdie on number 16 as he emerged from a duel Saturday with England's Paul Casey to finished with a seven-under 64.
"There's no secret that the more I'm smiling, the more I'm having fun, the better I'm playing," said Chappell, who finished the first two rounds at 11-under 131.
"I finished bogey-double bogey and kind of played my way out of the tournament (last Friday at The Barclays). I really was bothered by that and didn't want to let that happen again."
Casey parred the last two holes in his 66 to stay one stroke back and even with American Jimmy Walker, who fired a 64.
Brian Harman posted a 65 and is two back in solo fourth after taking the clubhouse lead with his impressive morning round.
The reigning US Open champ Dustin Johnson had a 66 and is three off the pace and tied for fifth with Smylie Kaufman, who also shot 66.
Patrick Reed, who won The Barclays last week to begin the FedEx Cup playoffs, recorded a 67 and was four shots behind in a six-way tie for seventh that included Rio Olympic gold medal champion Justin Rose of England, who also had a 67.
Chappell has never won on the US PGA Tour, but has finished runner-up three times in 2016, including a second at The Players Championship three months ago.
Chappell saved par on the final hole Saturday to equal the lowest score of the tournament so far.
He also holed out from 37 yards for eagle at the par-five, 600-yard seventh hole and collected six birdies opposite one bogey.
Chappell ranks 13th in the PGA playoff standings, but would vault into third if he is able to hang on through the next two rounds and win the event which finishes on Monday.
American Jordan Spieth shot 68 and Steve Stricker had a 69 and are both a shot back of Reed and Rose, tied for 13th.
Open champion Henrik Stenson shot 70 and is in a tie for 30th. World number five Rory McIlroy, of Northern Ireland, posted a 67 and also was tied for 30th along with Adam Scott, of Australia, who finished at 71.
World number one Jason Day, of Australia, missed a birdie putt on number 18 and finished at 71, making the cut on the number.
On Friday, Day's family was involved in a two-vehicle smash in Boston when their car collided with a bus. Day's wife, Ellie, was transported to hospital where she was treated and released. Day's two children were not injured.
Ellie sustained injuries in December after colliding with NBA superstar LeBron James while sitting courtside in Cleveland as James chased down a loose ball that went into the crowd. She was taken from the court on a stretcher and transported to a Cleveland hospital.
Phil Mickelson and two-time tournament winner Vijay Singh missed the cut on Saturday.