The No. 20 GPX Racing Porsche 911 GT3 R of Richard Lietz leads the Kyalami 9 Hour amid a sudden downpour that has seen teams scramble for wet weather tires.
Kevin Estre held a five-second lead over the No. 34 Walkenhorst Motorsport BMW M6 GT3 of Mikkel Jensen prior to the race’s fourth Full Course Yellow, due to an accident by the No. 108 Team M-Sport Bentley Continental GT3 of Rodrigo Baptista.
The clouds opened up moments later, amid thunder and lightning, forcing cars to re-enter the pits just moments after pitting under the initial FCY.
Lietz, now in the No. 20 Porsche, leads under safety car conditions ahead of Nicky Catsburg and fellow BMW driver Martin Tomczyk in third.
The No. 107 Bentley is now in the garage for a brake pad change after running in the top-10 at the time.
The Silver class-leading No. 6 Black Falcon Mercedes-AMG GT3 of Sergei Afansiev, meanwhile, spun under the safety car and got stuck on a curb.
Just over two hours remain in the race.