American John Hahn carded a brilliant 10-under-par 61 to claim a two-shot lead in the second round of the weather-delayed Africa Open on Friday.
Hahn fired eight birdies and an eagle at East London Golf Club to finish 16 under par, two shots ahead of overnight leader Ricardo Santos, who added a 66 to his opening 62.
Ranked 881st in the world, Hahn started from the ninth with a birdie and picked up further shots at the 14th and 18th before a brilliant scoring burst took him to the top of the leaderboard.
The 24-year-old birdied the first and second, eagled the par-five third and then birdied the fourth, sixth and eighth to effectively cover the front nine in just 28 shots, one outside the European Tour record.
A 95-minute delay caused by torrential morning rain meant the second round was not completed on schedule on Friday evening, with play due to resume at 0715 local time on Saturday.
Hahn, who gained his European Tour card by coming through three stages of the qualifying school, said: "I just got the putter hot early and it stayed hot all day. It turned into a good one."
Damien McGrane moved to six under par with a 69, a double bogey on the sixth slightly taking the shine off a round that included six birdies.
Michael Hoey is also on six under after a mixed round of 68, which had seven birdies, two bogeys and a double bogey.
Gareth Maybin and David Higgins both shot 68s to move to three and four under respectively but missed the five-under cut.
Kevin Phelan is also on three under after his round of 70.