Scott Jamieson fired an impressive 65 to join Alexander Björk leading in the clubhouse on a weather-delayed second day of the Tshwane Open at Pretoria Country Club.
Swede Björk was part of a three-way tie in top spot coming in to day two and while he fired a 67 to get to ten under, he soon had some company with Jamieson recording seven birdies and a single bogey.
Play was then suspended at 12.53pm due to thunder and lightning, with 14 of the first wave left with one hole to play and 37 players yet to complete their first. Play resumed at 13.50pm.
Thomas Aiken managed to get his round finished before the delay, firing a 62 that was the lowest of the week so far to leave him two shots off the lead alongside fellow South African Peter Karmis.
Jamieson has spent the last two seasons battling for his card, finishing 106th and 107th in the Race to Dubai Rankings presented by Rolex, but has a good record in South Africa, claiming his only European Tour win at the Nelson Mandela Championship presented by ISPS Handa in 2013.
For Björk, this is just his ninth event as he finds his feet on the European Tour after finishing seventh on last season's Road to Oman.
The 26 year old birdied the second for the second day in a row and while he dropped a shot on the fourth, further birdies were to follow on the sixth, tenth and 11th.
A brilliant right-to-lefter from off the green on the 12th then made him the first man into double figures and after dropping back with a bogey on the 16th, a smart up-and-down on the last moved him back to ten under.
Jamieson made birdies on the fifth, sixth, eighth and ninth to turn in 31 before dropping a shot on the 11th. Bounce-back birdies on the 12th and 14th followed and when the Scot put his approach to the 17th to four feet, he was tied for top spot.
Aiken started on the back nine and turned in 31 with birdies on the tenth, 12th, 13th, 15th and 18th. He then chipped in at the first, holed from the fringe at the second and hit a stunning approach to the third to make it four birdies in a row.
When he holed from six feet on the sixth, the whiff of a 59 was in the air, but a three-putt bogey on the next put paid to those hopes before he birdied the eighth.
Countryman Karmis fired a second consecutive 67 courtesy of a brilliant finish to his round. After gains on the third, fifth and sixth, he bogeyed the ninth and 14th before finishing birdie-birdie-birdie.
Another South African, Garth Mulroy, was heading up the last as the hooter sounded and he made par on his return to sit at seven under alongside Frenchman Grégory Havret, who had recorded a birdie in his first two holes.
Haydn Porteous was then yet to complete a hole at six under, a shot clear of Jamie Donaldson, Soomin Lee and Jordan Smith who were in the clubhouse.
