Defenders Phoenix Karaka and Storm Purvis set the tone early, shadowing the Tactix shooters and leaving its midcourters with little to work with.
The Steel never trailed in the match, comprehensively bouncing back from last week's 68-62 loss to the New South Wales Swifts.
It was the Southern franchise's fifth straight win against the Tactix, and the 12th in 15 games since the competition launched in 2008.
Leading 51-40 with a quarter to go, the home side all but had the game in the bag.
However, instead of taking the foot off the gas it blew the lead out to 61-44 in the first 5min of the quarter to seal the derby match.
Steel goal shoot Jhaniele Fowler-Reid became the franchise's all-time leading scorer just 3min into the match, notching her 1248th goal for the side in just her 28th match to surpass Daneka Wipiiti.
Trailing 16-11 after the first quarter, the Taxtix introduced Bailey Mes into the match in an attempt to find more space against Karaka and Purvis.
After the Steel scored the first three goals of the second quarter, Tactix defender Jessica Moulds made a couple of big defensive plays to help her side again pull to within five.
However, the home side raced out to a double-digit lead a few minutes later, after scoring five straight on the back of Karaka and Purvis intercepts.
Karaka finished the match with four intercepts and seven deflections, while Purvis had one steal and seven deflections.
Southern Steel 68 Jhaniele Fowler-Reid 56/60, Te Paea Selby-Rickit 8/11, Sophia Fenwick 4/11 Mainland Tactix 54 Mwai Kumwenda 34/38, Bailey Mes 17/24, Gemma Hazeldine 3/5. Quarter scores: 1st, 16-11; 2nd, 32-25; 3rd, 51-40.
