Sibonelo Makhanya scored 111 as the Northerns Titans declared on 515-9 against the Free State Knights in Bloemfontein on Friday.
Corbin Bosch (61) and Dayyaan Galiem (51) also made key contributions, while Alfred Mothoa took 5-62 for the Knights.
The hosts ended day two on 12-0, trailing by 503 runs.
At Newlands, Western Province collapsed from their overnight 306-6 to 315 all out. Proteas wicketkeeper Kyle Verreynne top-scored with 86, while Malusi Siboto (4-31) was the Central Gauteng Lions’ best bowler.
The Lions ended day two on 238-7 – still 77 runs behind WP – with Ryan Rickleton scoring 90 and Dominic Hendricks 76.
Beuran Hendricks (3-35) and Kyle Simmonds (3-91) fired with the ball for WP.
In Paarl, the Boland Rocks declared their first innings closed on 485-7 thanks to Stiaan van Zyl’s 127, Janneman Malan’s 99 and Hlomla Hanabe’s 47. Ndumiso Mvelase (4-104) was the North West Dragons’ best bowler.
The Dragons were 163-8 at stumps with Wesley Marshall unbeaten on 90. Spinner Siya Mahima, who opened the bowling, took 5-53.
At Kingsmead, the EP Warriors were unable to build on Rudi Second’s 120 with Eathan Bosch’s 5-75 restricting them to 386.
The Dolphins were 146-2 at stumps, with SJ Erwee (65*) and Marques Ackermann (18*) at the crease.
Dolphins vs Warriors scorecard
Division Two:
Mpumalanga Rhinos vs Eastern Storm