DULUTH, Georgia (AFP) - Five American players remained deadlocked atop the leaderboard after Friday's conclusion of the rain-disputed opening round of the 5.5 million-dollar US PGA AT and T Classic.

Of the five atop the leaderboard on six-under 66, only veteran Kenny Perry teed off in the afternoon, when heavy rain wreaked havoc on the course.

He remained on six-under after six holes of his second round, which began while those unable to finish Thursday due to darkness were completing their first tour at the TPC Sugarloaf layout.

Afternoon tee times Friday were delayed half an hour so it will be even longer before Jonathan Kaye, Ryan Palmer, Jonathan Byrd and Parker McLachlin return to action after enjoying more welcoming conditions Thursday morning.

No Friday finisher cracked the top 19 in the first round, with the leader of those coming into the clubhouse being England's Brian Davis, who nabbed a share of 20th on 69 before starting his second round.

Australian Gavin Coles completed a first-round 70 to stay within four strokes of the lead.

Thursday's later starters toiled through continuous rain, which stopped play once for half an hour.

The slow pace saw waits of up to half an hour on some tees, and play was eventually halted by the gathering gloom.

"It's always nice to catch a good end of the draw because it doesn't always happen that way," McLachlin said. "I've caught the bad end plenty of times when you have played in the morning and you are expecting it to be calm (but) it's really windy. And then right when you finish, the wind just dies down.

"You're like, 'That's not fair.'"

Perry shrugged off the miserable conditions to rebound from his fourth-round 81 at the Players Championship on Sunday.

He and John Mallinger, who fired a 68, were the only afternoon starters to complete rounds without a bogey.

Kaye, who was once ranked as high a No.14 in the world before injuries stalled his career, finished with two birdies to join the leading group.

Charles Howell and David Toms were among a group of four players who were one shot off the pace on five-under 67.

Defending champion Zach Johnson was two under through eight holes before the rain delay and eventually finished tie for 20th after a 69.

Last year, Johnson beat Japan's Ryuji Imada on the first hole of a playoff for his second win of the season in Georgia.

He had won the Masters earlier in the season for his first major title.

Johnson also won this event in 2004 and tied for second in 2006.