Swallows won an enthralling encounter by 13-10 to progress to the semi-finals.
In the other quarter-finals, College Rovers lost by 24-36 to Durbell in Durban, the Northam Platinum Rhinos beat Multisure Gardens by 35-29 and Newrak Rustenburg Impala were too strong for Welkom, winning 48-19.
The semi-finals will be contested on Saturday, 6 April (venues TBC) - it will be Durbell up against Swallows, and Impala taking on Rhinos.