FORT WORTH, Texas, May 24, 2013 (AFP) -Kuchar was one shot in front of clubhouse leader Graham DeLaet, who played early and completed a three-under par 67 for a nine-under total of 131.
Canada's DeLaet finished his round before a delay for threatening weather halted play for more than two hours.
He teed off on 10 and his round included three straight birdies at the 18th, first and second before he made three bogeys at Colonial's "Horrible Horseshoe" of holes three, four and five.
"It definitely got me today," DeLaet said of the stretch of holes that is traditionally Colonial's toughest.
He capped his round with birdies at eight and nine, however.
At the eighth, his 17th, DeLaet drained a 28-footer for birdie, then poured in an 11-footer at the ninth.
"I played well on my first nine. I stumbled a bit on the second nine, and just wanted to make a par at the sixth ... to calm the nerves," he said. "Great birdies at eight and nine to finish."
His nearest rivals in the clubhouse were Jordan Spieth (67), Josh Teater (67) and Steve Flesch (64) on eight-under 132.
Ryan Palmer was eight-under through 12 holes when play was halted for a second time late in the day, with organizers opting to suspend the round for the night.
Palmer, the overnight leader after a sizzling 62 on Thursday, was at nine-under for the tournament until a double-bogey at the par-four fifth, where he had to take a penalty shot after a wayward shot off the tee.
He then followed with a bogey at the sixth, but got back on track with birdies at 10 and 12.
Kuchar was a bogey-free five under through 15 holes for the day.
Kuchar opened his round with a two-putt birdie at the first, and made a short birdie putt at the second.
He holed a shot from off the green at the fifth and made a 30-footer for birdie at the seventh and picked up another birdie at 14.
"I really got off to a great start. And then I kept playing some good golf," Kuchar said. "This course can give you trouble, but if you are hitting it good, you can make some birdies out here."
The American had just struck his tee shot at the par-three 16th when the horn blew.
The 54 players who were on the course were to resume the second round on Saturday morning.
Spieth's 67 came despite a one-stroke penalty assessed after his ball fell into a spike mark on the sixth green after he addressed it.
"It's an unfortunate ruling," Spieth said. "That's just how it goes."
Partial second-round scores on Friday in the weather-disrupted second round of the $6.4 million US PGA Crowne Plaza Invitational (Play halted for day by inclement weather with 54 players on course, round to resume Saturday. USA unless noted, par 70):
131 - Graham DeLaet (CAN) 64-67
132 - Josh Teater 65-67, Jordan Spieth 65-67, Steve Flesch 68-64
133 - Freddie Jacobson (SWE) 66-67, Chris Stroud 67-66
134 - Boo Weekley 67-67, John Rollins 63-71, Ken Duke 66-68, Scott Stallings 69-65, Chez Reavie 70-64, Matt Every 65-69
135 - Brian Davis (ENG) 67-68, Derek Ernst 66-69, Jim Furyk 69-66, Roberto Castro 67-68, Justin Hicks 71-64, Charlie Wi (KOR) 69-66, John Peterson 64-71
136 - Tim Clark (RSA) 67-69, David Lingmerth (SWE) 72-64, J.J. Henry 68-68, Martin Flores 66-70, Brandt Jobe 68-68, Jeff Overton 67-69, Brendon de Jonge (ZIM) 66-70