Proteas spinner Keshav Maharaj took 5-62 as the KZN Dolphins bowled out the Free State Knights for 165 on day two of the 4-Day Series match in Bloemfontein.
Ottniel Baartman (3-23) and Andile Simelane (2-17) provided good support with the ball.
The hosts had started the day on 53-0 in reply to the Dolphins’ first-innings 253, with Matthew Kleinveldt on 40*.
But he added just three runs to his overnight total before being clean-bowled by Baartman.
Maharaj then trapped Isaac Dikgale lbw for 24 and the wickets continued to fall, with the only other notable contribution coming from Migael Pretorius (29).
The Dolphins were 37-0 in their second innings at stumps, leading by 125 runs, with Sarel Erwee 17* and Tshepang Dithole 20*.
At the Wanderers, Sinethemba Qeshile struck 124 as the EP Warriors posted 438 in their first innings against the Central Gauteng Lions. Jordan Herman (71) and Rudi Second (70) scored half-centuries.
Lutho Sipamla took 4-77, while Wiaan Mulder and Bjorn Fortuin picked up two wickets each.
The Lions were 19-0 when rain ended play for the day.
The other two matches, between the Northerns Titans and Boland Rocks at Tuks in Pretoria and the North West Dragons and Western Province in Potchefstroom, have yet to begin due to rain and wet outfields on the first two days.