SEA ISLAND, November 9, 2013 (AFP) - Kirk's eight-under par total of 132 put him one ahead of 2012 US Open champion Webb Simpson, fellow Americans Briny Baird and Kevin Chappell and Australian John Senden.
Kirk played in the worst of the windy conditions but managed to nab five birdies on the back nine, which included a 40-foot putt from off the green at the 11th -- his second hole of the day -- and a chip-in from 60-feet at 14.
Senden's day was highlighted by an eagle at the par-five 15th, and he finished the final hole of his second-round 67 in near darkness to join the group on 133. Play was then halted.
Chappell had an eagle and four birdies to offset two bogeys and a double-bogey at the par-three third in his two-under 68.
Baird, meanwhile, had four birdies and four bogeys in his even par 70, while Simpson kept mistakes to a minimum despite the blustery conditions, scoring just one bogey along with three birdies in his 68.
The tournament fell behind schedule on Thursday, with a two-hour fog delay in the morning.
George McNeill returned Friday morning to finish a first-round 62 that gave him the lead, but he ballooned to a 76 in a second round that included a run of five straight bogeys.
His was not the only score that soared, and Chappell counted himself lucky to get his two-under effort in early.
"You hit some not-so-perfect shots and get some bad breaks with the wind gusting and you get exposed really quickly," Chappell said. "I was fortunate to come to that realization that there's some luck involved today and that maybe for a period of time I was one of the luckier guys out here."
Simpson, whose victory in October in Las Vegas was his first win since his major breakthrough at Olympic Club in 2012, was also more than pleased to find himself under par after such a trying day.
"Before I played, I would take anything under par," he said. "The game plan before the round was to know club selection so you don't get to a hole and you're shocked and you don't know what to do."
Leading partial scores on Friday in the second round of the US PGA $5.5 million McGladrey Classic (Round halted by darkness, to resume Saturday. USA unless noted, par-70):
132 - Chris Kirk 66-66
133 - Kevin Chappell 65-68, Briny Baird 63-70, Webb Simpson 65-68, John Senden (AUS) 66-67
134 - Jason Kokrak 69-65, Scott Brown 66-68, Ted Potter 67-67, Tim Clark (RSA) 67-67
135 - Brian Harman 67-68, Matt Every 67-68, Brian Gay 63-72, Jonathan Byrd 66-69
136 - Matt Kuchar 68-68, Will Claxton 65-71, Kevin Stadler 68-68, Boo Weekley 67-69
137 - Lee Dong-Hwan (KOR) 67-70, Scott Langley 66-71, Ben Curtis 68-69
138 - Martin Flores 70-68, George McNeill 62-76, Harris English 68-70, Heath Slocum 67-71, Zach Johnson 70-68, Stuart Appleby (AUS) 68-70