McGirt and Piercy, who shot a 3-under 67 after a course-record 62 on Thursday, finished 36 holes at 11-under 129. The pair is one stroke ahead at Hamilton Golf & Country Club.
McGirt parred his first three holes, then ran home an 8-footer for birdie at the fourth. That was the start of a great run for McGirt as he birdied the next two holes, including one from off the green at six, to reach 10-under par for the championship.
McGirt notched another par at No. 7, then made another birdie from off the green at the eighth.
He parred the first four holes on the back nine, but made a mistake at the 14th. Calling it “probably the best swing I’ve made all week,” McGirt hit a 7- iron just over the flag, but the ball hopped over the green. He made bogey to fall back to 10-under.
McGirt atoned for the error with a beautiful approach inside two feet at the 15th. He tapped in for birdie, then parred out to get into unfamiliar territory on the PGA Tour.
He’s never owned a piece of the 36-hole lead on tour and in fact, his tie for fifth last week at the True South Classic was his best finish on the PGA Tour.
McGirt played several mini-tours in his early career, but this is his second full season on the big stage, something he doesn’t take for granted.
“All those years where you’re playing for basically less than your full entry fee, yeah, you kind of learn to appreciate everything that comes with being on the PGA Tour,” said McGirt. “I understand what we have out here, and trust me, I don’t want to go anywhere else.”
Robert Garrigus carded a 4-under 66 and is alone in third at minus-10.
Bo Van Pelt holed his approach for an eagle at his final hole Friday and signed for a 66. He is fourth at 9-under par.
Tim Clark matched Piercy’s course record from Thursday with a 62. Clark is knotted in fifth with Vijay Singh (67) and Josh Teater (65) at 8-under 132.
Newly minted Open Champion Ernie Els played better on Friday, but his even-par 70 won’t be enough to make the cut. He came in at 2-over par and will have the weekend off to prepare for next week’s WGC-Bridgestone Invitational.
With Els missing the cut, those playing on the weekend will have to catch two relatively unknowns.