Garnett has gone from Daviess County Country Club and then Missouri Western State to leading at Hogan’s Alley after two rounds at Colonial.
After starting with an eagle, Garnett shot a 4-under 66 on Friday and moved to 7-under 133. He had a one-stroke lead over long-putting Chris Stroud (64) and Robert Streb (68).
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, Missouri, 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.
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.
SENIOR PGA CHAMPIONSHIP
BENTON HARBOR, Mich. (AP) - Tom Watson shot a 3-under 68 for a share of the lead in the Senior PGA Championship with fellow Hall of Famer Bernhard Langer and Colin Montgomerie and three other players.
The 64-year-old Watson, playing alongside Langer and Montgomerie, had five birdies and a double bogey - on the par-4 12th - to reach 4-under 138 after two rounds at Harbor Shores. Trying to win for the first time since the 2011 Senior PGA, Watson is coming off a sixth-place tie last week in the Regions Tradition in Alabama.
Langer also had a 68, and Montgomerie shot 69 to join Watson, Bart Bryant, Steen Tinning and Kiyoshi Murota atop the leaderboard. Bryant shot 67, Tinning 66, and Murota 65.
Murota, from Japan, had the best round of the day, chipping in for eagles on the par-5 fifth and ninth.
Bryant bogeyed the 18th hole to drop into the tie for the lead.
AIRBUS LPGA CLASSIC
MOBILE, Ala. (AP) - Catriona Matthew remained atop the Airbus LPGA Classic leaderboard, birdieing four of the last seven holes to take a one-stroke advantage over Charley Hull into the weekend.