Updated

Damien McGrane and Jamie Elson under 63s on Thursday en route to the clubhouse lead at the opening round of the suspended Joburg Open.

Thunderstorms forced a lengthy delay of nearly five hours before darkness suspended play at Royal Johannesburg and Kensington Golf Club, where golfers are on both the East and West Courses over the first two rounds. For the last 36 holes, only the more difficult par-72 East Course is used.

With some gloomy weather forecasted over the weekend, it remains to be seen if there will be more delays ahead. The second round will resume at 6:45 a.m. local time, 11:45 p.m. (et).

The East Course lived up to its name in its brief usage on Thursday, with 19 of the top 21 players on the leaderboard playing on the par-71 West Course.

McGrane and Elson were two of them, though one of their closest competitors, Desvonde Botes, posted a seven-under 65 on the East Course. Reinier Saxton and Peter Karmis had a seven-under 64s on the West Course and share second, while Joel Sjoholm, David Drysdale, George Coetzee, George Murray, Carlos Del Moral and Shaun Norris posted six-under 65s on the West Course.

The week's storyline is reigning Masters champ Charl Schwartzel, who began his surprising 2011 season with his second straight Joburg Open title. The top- ranked player in the field by a considerable margin at No. 9, Schwartzel is even-par through 15 holes on the East Course.

It was McGrane and Elson, however, who stole the show Thursday. McGrane is looking for his first European Tour victory since the 2008 China Open, while Elson gained his tour card for this year by holing a 40-foot birdie putt on the final hole at qualifying school.

"I am delighted to be in a good position after round one," McGrane said. "For the last three or four years, Irish golf has been quite incredible, and I think we feed off each other. For a small nation, it sure is great to be there or thereabouts."

McGrane's day could have been even better if not for a bogey at the last. He had five birdies in a flawless front nine and added back-to-back birdies from the 11th to get to seven-under.

He moved to nine-under with an eagle at the par-five 15th, but lost a stroke at the last, one that could cost him with Botes hot on his tail.

"I stacked up a few birdies during the round, but that eagle really turned my round," McGrane said.

Elson started with four consecutive birdies and added two more at the sixth and ninth to make the turn at six-under. He began the back nine with two bogeys, but had four birdies in his last seven holes to tie McGrane.

Botes, who has 12 international victories but none on the European Tour, had five birdies and an eagle on the East Course, which means he'll have an opportunity to build on his score on the easier West Course.

His last victory anywhere came at the 2003 Parmalot Classic.

Schwartzel, who has not won since his Masters triumph, got off to a rocky start with bogeys at the first and fourth. His first birdie came at the sixth, but he followed with his third bogey of the day.

A birdie at the ninth put Schwartzel at one-over, but he finally got under par for the first time with birdies at the 12th and 14th. A bogey at No. 15 dropped him to even-par before the round was halted.

NOTES: After Schwartzel, the highest-ranked player is Retief Goosen at No. 50. He shot a five-under 66 on the West Course and is tied for 10th...Schwartzel is attempting to become the sixth European Tour player to win the same tournament three straight times.