Robert Rock took a one-shot lead at the Joburg Open on Friday before rain interrupted play for a second straight day.
The Englishman shot a 4-under 67 on the West Course to move to 11-under 132 overall after completing his first round on the East Course early Friday. That left him one ahead of South African pair Jbe Kruger (66) and Branden Grace (66).
More than half the field was still to finish their second rounds when strong wind and heavy rain lashed Royal Johannesburg and Kensington Golf Club and ended play.
Overnight co-leader Jamie Elson was one of 12 players still to tee off.
Two-time defending champion Charl Schwartzel was 3 under after two rounds.