Sweden's Johan Edfors turned in a five under par 31 to hold the early lead in the first round of the Ballantine’s Championship before poor visibility caused a suspension in play.
Edfors birdied the third and fourth holes before picking up further shots on the sixth, eighth and ninth, but his momentum was halted by the suspension in play at 10.50am which forced the players off for two hours and ten minutes, before resuming at 1pm. All afternoon tee times are delayed by two hours and 30 minutes.
A three-time winner in his rookie year in 2006, Edfors has only made two cuts in seven appearances so far in 2013, but was one shot clear of Frenchman Jean-Baptiste Gonnet.
Gonnet had only broken 70 once in 2013 away from the course-shortened Nelson Mandela Championship, but birdied the third, fourth, sixth and ninth at Blackstone GC to be four under through 15 holes.
Edfors's compatriot Karlberg set off at even hotter pace with four birdies in his first four holes, before paring the next three and dropping a shot on the eighth to lie amongst a group of players on three under par.
Defending champion Bernd Wiesberger was three under through 13 holes, having carded three birdies in his front nine after starting on the tenth tee. He gave one back with a bogey on the first but then added another birdied to his card on the fourth, finishing the hole after the suspension was called.
Italian Ryder Cup star Edoardo Molinari and South African former Open Champion Louis Oosthuizen were among the later starters.