Jimmy Walker is moving on up the leaderboard all the way to the top at the World Golf Championships-Bridgestone Invitational after Friday's second round in Akron, Ohio.
Walker endured nearly five hours of storm delays and shot a 5-under-par 65 at Firestone County Club's South Course to take a one-stroke lead over Thomas Pieters of Belgium.
After 36 holes, Walker was parked at 7-under 133. Pieters, the first-round leader, slipped two back into sole possession of second place after he followed Thursday's 65 with a 70.
Three behind the leader in the 76-player field are Northern Ireland's Rory McIlroy, Zach Johnson, Japan's Hideki Matsuyama, Charley Hoffman, Canadian Adam Hadwin, Scotland's Russell Knox and Sweden's Alex Noren. Johnson and Matsuyama each finished with 67 and McIlroy had a 69.
Four strokes back are Jordan Spieth, the British Open champion who finished the round with two birdies for a 70, and Jason Day, whose 30 on the front side propelled him to a 66.
Walker suffers from Lyme disease that causes fatigue and loss of concentration. But he maintained his focus through the delays to make six birdies and just one bogey.
The defending PGA champion and six-time PGA Tour winner has only one top-10 finish this year in 18 events.
"To me, it's important to have a good week because I haven't had a lot of them," Walker said. "But I feel the game is trending in the right direction and the day was a good one."
The 25-year-old Pieters, who tied for fourth in the Masters in April, opened the second round with a bogey that was immediately followed by a birdie. He began the back nine with a birdie at No. 10 and slipped back to par for the day with a bogey on the par-3 15th hole.
Johnson made five birdies and two bogeys. Three of those birdies came at par-3 holes. He is seeking his first career title in a WGC tournament.
Day's hot start included three consecutive birdies and then two more to make the turn in 5-under 30. Day is looking for his first win in 2017.