Sheldon van der Linde led the Kyalami 9 Hour at the opening hour of the race, in a BMW M Team WRT 1-2 following a hard-fought battle with the pole-sitting No. 999 GruppeM Racing Mercedes-AMG GT3 Evo.
The South African held a 2.182-second advantage over teammate Augusto Farfus with 60 minutes in the books.
Van der Linde took over the lead on Lap 9 following team orders that swapped the positions of the two factory BMW M4 GT3s and extended the margin over Maro Engel.
While having initially held the lead at the start, Engel came under attack by the BMWs, which appeared to hold a pace advantage following a pre-race Balance of Performance adjustment for the Mercedes.
Farfus, in the No. 33 BMW, took over second on Lap 11, which saw Engel drop behind in the fight with the pair of Tressor Attempto Racing Audi R8 LMS GT3 Evo IIs.
The No. 4 Grove Racing Porsche 911 GT3 R of Brenton Grove led Pro-Am after a challenging start for Kenny Habul in the class pole-sitting No. 75 SunEnergy1 by SPS Mercedes.
Habul dropped to ninth overall on the opening lap but clawed his way up to sixth at the end of the hour.
The No. 3 NGK Pablo Clark Racing Mercedes of Mikaeel Pitamber won the Kyalami Supercup race-within-a-race, which concluded at the one-hour mark for three of the 13 entrants.