KJ Choi shot to the top of the leaderboard at the RBC Heritage although much of the field will have to wait until Saturday to complete their second round after heavy rain in South Carolina forced play to be suspended midway through Friday.

Choi was the standout performer at the Harbour Town Golf Links course with a round of 67 that took the South Korean to five under par overall on a day where many of his fellow professionals struggled in the inclement conditions.

The rain eventually ensured play was abandoned at 2.54pm local time, with PGA Tour vice president of rules and competition Slugger White hopeful of completing the second and third rounds on Saturday.

He told the PGA Tour's official website: "We can't play anymore. It's pretty bad out there right now. We have a little drying trend between 4am and 2pm if all goes well.

"We probably have about four hours left of golf (to finish round two) and if we can start tomorrow at 8am, we'll try to turn it around and get the third round in and get back on track Sunday somewhere."

Australia's Robert Allenby is just one shot behind Choi although he only completed five holes before the weather intervened, while England's Luke Donald is one of five players on three under par overall following his 69.

Scott Langley, who held the joint overnight lead alongside Matt Kuchar and William McGirt, was level with Donald after a two-over-par 73.

McGirt slipped off the pace after following up his first-round 66 with a 76 on Friday to sit on level par, while Kuchar was just a shot better off after six holes following double bogeys at the fourth and sixth.

Defending champion Graeme McDowell moved to two under after six holes, while Scottish pair Russell Knox and Stephen Gallacher will also hope to complete their rounds in the morning after struggling on Friday.

Knox slipped back to level par after two bogeys on the back nine, while Gallacher dropped four shots to sit one shot below the projected cut line of three over par.