Vijay Singh, bidding for his first PGA Tour victory of the year, relied on his belly putter while grabbing a one-shot lead in Friday's second round at the WGC-Bridgestone Invitational.
Three strokes off the pace overnight, the smooth-swinging Fijian fired a four-under-par 66 at Firestone Country Club to take control at the tournament's halfway point.
Singh compiled five birdies and one bogey in relatively calm conditions for a seven-under tally of 133 in the prestigious World Golf Championship event.
The former world number one is a stroke in front of second-ranked American Phil Mickelson who also carded a 66.
Australian Peter Lonard birdied three of the last four holes for a matching 66 to lie one shot adrift, level with Americans Zach Johnson (68) and Sean O'Hair (67) and Britain's Lee Westwood (65).
Singh, who ended Tiger Woods's five-year reign as world number one in September 2004, was delighted to take the lead despite struggling for accuracy off the tee.
"Two different days," the 45-year-old told reporters after finding only six fairways out of 14 compared with 13 in the opening round.
"Yesterday I drove the ball and couldn't miss a fairway and today I couldn't find one, so that was a big difference. I felt very comfortable on the tee, I just don't know what happened.
"My iron play was the same. I struck them really well and I putted decent."
PUTTING FORM
Singh, seeking his 32nd victory on the PGA Tour, totalled only 28 putts as he again flourished on the greens with his belly putter.
"I worked a lot on my putting last week and a few weeks ago and decided I'm going to stick to a belly putter," he said. "I've been going back and forth and couldn't get any consistency out of it.
"The British Open was a turning point where I played really well and putted really badly," he added, referring to his missed cut at Royal Birkdale two weeks ago.
"I decided: 'That's it, I'm not a good putter with a short putter.' So that's why I've been playing with a belly. And my iron play is really good right now, so that's driving me through."
Mickelson, the highest-ranked player in the elite field of 80 in the absence of injured world number one Tiger Woods, was delighted with his improved performance on and around the greens after an indifferent last month.
"I feel much, much better with the putter and much better with the wedges," the 38-year-old Californian said.
"I hit some great wedge shots today, just the basic little chip shots that I expect to get close. I spent last week on short game exclusively and I feel like it's starting to come around."
South African Ernie Els, Mickelson's playing partner for the first two days at Firestone, followed his opening 69 with an error-strewn 74 to slide to three over.
Overnight leader Retief Goosen of South Africa, who set the pace with a 66, also struggled to maintain his form, a 71 leaving tied for 12th at three under.