American Scott Piercy moved up alongside world number one Jason Day at the top of the leaderboard after the third round of the WGC-Bridgestone Invitational in Ohio.
Piercy, in a three-way tie for second at the US Open last month, opened up with an eagle on the second hole at the Firestone Country Club, Akron on his way to a three-under-par 67 - which would have been one stroke better and given him the outright lead but for a bogey on the 18th.
Day, meanwhile, carded a one-under 69 for a five-under total of 205 as he recovered from successive bogeys at the end of the front nine by sinking a 35-foot eagle on the 15th.
The Australian managed to find only three fairways, but remains positive heading into Sunday's final round.
In an interview on www.worldgolfchampionships.com, he said: "I hit some pretty errant shots out there, but the short game saved me.
"I was just trying to play the draw and there was a section in my round where I just kept on losing everything right and getting myself into some trouble.
"There are a lot of negatives you can look at this round with regards to my hitting, but the positive is that I am still tied for the lead and have not hit the ball well all week.
"If I can hit it anywhere sort of decent tomorrow, give myself a few more opportunities on the green, I feel I have a really good chance of winning."
Swede David Lingmerth is in third place following his 69 which left him at four under, with American Brian Stuard two shots further back.
US Open champion Dustin Johnson climbed 17 places to a tie of fifth place with a best-of-the-day 66.
Jordan Spieth hit a triple bogey eight on the 16th, to sign for a 71 which leaves the 2015 Masters champion at even par.
Ireland's Shane Lowry shot a 70 and lies toed for 40th on eight-over-par.