FORT WORTH, Texas -- PGA Tour rookie Brice Garnett grew up in a small Missouri town where his home course is a nine-hole layout.
Garnett has gone from Daviess County Country Club and then Missouri Western State to leading at Hogan's Alley after two rounds at Colonial.
"I'm just keeping my head down and trying to make as many birdies as possible," Garnett said. "I'm going to try to embrace it this weekend and have fun, and we'll see where we stand come Sunday."
Adam Scott, playing as No. 1 in the world for the first time, had birdies on three of his last seven holes for a 68 to get to 1 under. He has made the cut in his last 34 PGA Tour events, the longest active streak.
Matt Kuchar, ranked No. 4 in the world, had a chance to move to the top with a victory. But he missed the cut by a stroke at 2-over 142 after a 70.
The 30-year-old Garnett is from Gallatin, Mo., a town of about 1,800 people. He has only one top-10 finish in his 18 previous starts on the PGA Tour, and has never won on the Web.com Tour. This is the first time he has even been in the top 10 after the second or third round on the PGA Tour.
"I think each and every week the rookies feel more comfortable. I know I have," Garnett said. "You can't get down on yourself being a rookie. ... It's been fun, and I'm learning each and every day."
First-round leader Dustin Johnson (70) dropped into a seven-way tie for fourth at 5 under. That group also included Texas resident Jimmy Walker (68), a three-time winner this season and No. 1 in the FedEx Cup standings.
Walker had a strange occurrence when his tee shot at the 17th hole appeared to nick a bird in flight -- though the bird kept flying before Walker made another par.
"We saw (the ball) fly the whole way and then it kind of disappeared over the trees," said Walker, the only player still without a bogey this week. "I didn't see it."
Stroud made five putts from over 20 feet, all coming in his last 12 holes. His made putts in the round combined for just under 221 feet, the most on the PGA Tour since Brent Geiberger covered 240 feet during the first round at Booz Allen in 2006.
And Stroud did that using a new putter he picked up this week.
"It has no lines on it. ... I've been using another, but it had a bunch of lines on it," Stroud said. "I simplified my putting. Get over it, line up and try to bring the putter back square and back to the ball square at impact. I've just been rolling it beautifully."
Stroud drained a 16-footer on the 193-yard 13th hole, his third birdie of the day coming on his fourth hole. The Texas native was just getting started, with his first 20-footer coming at the par-3 16th when he made birdie from 23 feet.
There was a 22-footer for birdie at the par-5 No. 1 hole, and he rolled in a 56-footer across the green at No. 4, the difficult 211-yard par 3. There was a 26-footer at No. 6 and yet another long birdie putt at his last par 3, a 34-footer at No. 8.
"My driver has been bad. ... I've hit it terrible the last two days. Really, really bad. But putted awesome," he said. "So I don't have to worry about the greens. I just need to get the ball on the greens. Usually it's the opposite. I usually hit the ball really well and struggle to get the ball in the hole."
On his final hole, the 406-yard dogleg-right ninth, Stroud's approach was well left into a bleacher area near a concession stand. After a free drop and pitching to about 26 feet on the fringe, he two-putted from 26 feet for bogey.
Tim Clark was 7 under and tied for the lead after four consecutive birdies only six holes into his round of 68. But he three-putted at the par-3 16th and didn't have another birdie until No. 9, his last hole, to get to 5 under and tied for fourth.