Action was resumed after a weeklong break, which also saw a good win for DHL Western Province over the past weekend.
Playing first on Friday, the Lions defeated the Hollywoodbets Sharks 39-24 in their late morning meeting in Durban.
On Saturday, WP outplayed the Leopards 31-17 for a good away win in Potchefstroom.
In completing the round-four action, the Bulls outplayed the Toyota Cheetahs 33-22 in Bloemfontein for their fourth win of the season.
The fourth-round results leave the Bulls and Lions locked on 20 points each in the first two position on the league table, with the defending champions from Pretoria in first position by virtue of a better points’ difference.
The Gauteng rivals are followed by WP on 10 points, Sharks (seven), Cheetahs (five) and the Leopards, who must still get off the mark.
Two matches are scheduled for this Friday, starting with the meeting between Bulls and Lions from 10h30 at Loftus B in Pretoria, and followed by the clash between Free State and WP at 12h30 in Bloemfontein.
Saturday sees the Sharks and Leopards battle it out from 11h00 at KP2, Hollywoodbets Kings Park in Durban.