Jorge Campillo and Colin Nel both shot rounds of 59 at the Nelson Mandela Championship in Durban on Friday.
Campillo's amazing effort vaulted him into tied second place - a shot behind leader Daniel Brooks - while Nel's was 18 shots better than his first round 77.
No-one has ever broken 60 on the European Tour but it was soon confirmed that the two 59s would not count as official records because they were achieved using preferred lies and from a reduced par.
Tournament organisers had chosen to reduce the event to 54 holes on Friday due to the heavy downpours which had interrupted play and left the fairways waterlogged.
There was a further delay on day three of a four-day tournament that was brought forward to a Wednesday start to avoid a clash of its final round and Sunday's funeral of former South African president Mandela.
The handful of players who had not completed their first rounds were due out from 6am local time, but they did not make it to the tee until 9am at the Mount Edgecombe Country Club.
When they did finally get in play, Campillo fired eagles on the fourth and 12th holes along with seven birdies in his flawless 11-under round on the new par of 70 while Nel also eagled the 12th and racked up nine birdies.
"My caddie walked the course during the practice round and said we could shoot 59 out here," Campillo said. "It's a great day. I was nervous on the finish, but I managed to finish strong. I'm really happy because no matter what you still have to make the putts to shoot 59."
It looked as if Campillo's 11-under 59 would see him end the day tied for the lead with England's Matthew Baldwin (62) but 27-year-old Englishman Brooks, who led the way after round one following a 62, reached 12-under after 11 holes of his second round before fading light halted play.
A trio of South Africans - Branden Grace (66), Oliver Bekker (66) and Dawie Van Der Walt - share fourth place on 10-under, two shots back, with Van Der Walt having five holes of his second round to complete.
The early finish means the players who are still to finish their second round will resume at 6am on Saturday, before the third and final round begins after 9:15am.