Chris Paisley and Chase Koepka carved into Jacques Kruyswijk's lead following strong starts to their second round at the BMW SA Open Championship Proudly hosted by the City of Ekurhuleni.
Englishman Paisley recorded back-to-back birdies at the sixth and seventh in his first eight holes and American Koepka carded one under after six as the pair moved just one shot adrift of Kruyswijk, alongside overnight co-leader Branden Grace and Scott Vincent for a four-way tie at eight under par.
Kruyswijk, who earned his playing privileges at the European Tour through Qualifying School in November, recorded seven gains and two bogeys on his way to a second round 67 at Glendower Golf Club.
The World Number 400 opened up with back-to-back birdies from the tenth to move to six under but dropped shots at the 12th and 17th hauled him back to four under before a gain at the 18th brought him back in contention.
He sealed a hat-trick of birdies from the second with a lengthy putt for a share of the lead at eight under with Zimbabwe's Vincent, compatriot Grace and Nacho Elvira, and when he picked up a shot on the penultimate hole, he was in front on his own.
Vincent carded the round of the morning as he rattled in seven birdies and one bogey to register an impressive 66.
Birdie at the par five second before three successive gains from the seventh moved him to six under and two strokes behind then-leader Grace.
A birdie-bogey from the 11th kept Vincent at six under before he hit a stunning second shot on the par five 15 for an eagle chance. The 26 year old had to settle for a birdie, and followed that up with another gain at the next to earn a share of the lead.
Grace started the day on seven under alongside Koepka, younger brother of 2017 US Open Championship winner Brooks, but when he birdied the par four third, he was the leader.
The World Number 30, who recorded a trio of eagles in a colourful first round of 65, was briefly joined at the top by compatriot Justin Walters on eight under when he was at the turn, but as the 37 year old fell away, Grace carded his second gain at the 17th to lead only to give that shot back at the last.
Defending champion Graeme Storm is in danger of missing the cut, despite recording a 70 during his second round, as he sits on one over par.
Spain's Elvira is in sole sixth place at seven under following three birdies and a bogey for a score of 70.
Walters is a shot further adrift with South Korea's Soomin Lee, Italian Renato Paratore, South Africa's Rhys West and two-time US Open Championship winner Retief Goosen, who is three under after five holes on the second day.