Robert Rock (Getty Images)
England's Robert Rock shot a second round 67 to move into the lead at the Joburg Open before play was again suspended.
The 34 year old, playing on the West Course, is 11 under par for the tournament after posting an eagle and four birdies, with the only blemishes being bogies on the eighth and 12th holes.
Rock, chasing a second professional win, signed his card a shot clear of home duo Jbe Kruger and Branden Grace, who both went round the West Course in 66, adding to their opening 67s.
Overnight leaders Damien McGrane and Jamie Elson were still waiting to start their second round by the time the leaders returned to the clubhouse, while a four under 67 on the West layout from Scotland's Scott Jamieson left him three shots adrift of Rock.
South African Michiel Bothma joined his compatriots in jostling for position at the top of the leaderboard, with a five under 66 leaving him two shots behind Rock.
After a four-hour delay on the first day due to thunder, the weather struck again at 11.37 GMT to force the players back to the clubhouse.