American John Hahn carded a 10-under-par round of 61 to take a two-shot lead on a rain-affected second day at the Africa Open.
Overnight leader Ricardo Santos of Portugal started brightly and was two shots clear at the top of the leaderboard when players were forced from the course for 90 minutes by adverse weather conditions.
But Hahn completed the final nine holes of his round in just 28 shots to storm to the front of the pack at 16 under, hitting eight birdies and an eagle along the way.
The delay meant some players were unable to finish the day's play, and will be forced to resume their second round on Saturday.
Santos' interrupted round saw him go four worse than his first-round score of nine under, while Oliver Fisher of England moved into third by finishing with four consecutive birdies.
And it was a day of perfection for the field's leading golfers, with no member of the top five, completed by David Horsey and Fabrizio Zanotti, posting a single bogey.
Despite seeing his lead slip away on day two, Santos revealed he felt the weather had played into his hands.
"I was very pleased to score so well today," he said. "I really couldn't ask for much more.
"I got quite lucky with the weather delay, because I was in some thick rough when we were called off, but the break let me breathe some clean air and when I came back out I saved par.
"There is still a lot of golf to come, but I'm very happy with my position at the moment."
Fisher was also thankful for the rain delay, adding: "I got off to a good start and then got called in on the fourth fairway.
"I made two birdies straight after that, so the delay helped me a little bit. I went dry for a while mid-round and then finished with four birdies, so it was a good day."
Wallie Coetsee and Sihwan Kim are among the players perilously poised a shot above the cut with holes left to play on Saturday, while Magnus A Carlsson and Louis de Jager will be among those hoping to make it into the second half of the tournament.
Wade Ormsby was the only Australian to make the cut and is in a tie for 19th place at eight under.