The strong Tactix defence, led by the relentless Temalisi Fakahokotau and captain Jane Watson, continued to carry the Mainland side.
And with a considerable lift from Tactix midcourters Kimiora Poi and Erikana Pedersen, shooters Ellie Bird and Brooke Leaver were provided with plenty of opportunities.
However, the familiar problem of low shooting percentages returned to plague the team as the duo continued to miss critical goals.
Showing more mobility on attack and a big lift on defence, led by captain Wendy Frew, the Steel clawed back lost ground.
But an early knee injury to towering Steel shooter Jennifer O'Connell, who collided with the intercept-hungry Fakahokotau, saw the Tactix pull ahead again to take a 30-26 halftime lead.
Steel coach Reinga Bloxham called Olivia Bates on to the court in place of O'Connell but the young shooter struggled.
With hesitant play from the Steel allowing the Tactix to extend their margin, a strapped-up O'Connell returned to the shooting circle.
But even O'Connell's tidy 85 per cent success rate wasn't enough to regain the advantage as the Tactix led by six after three quarters.
But well-known for their grit and determination, the Steel stormed back in the final quarter, with the Selby-Rickit sisters anchoring each end of the court.
The seamless flow the Tactix had established was disrupted and suddenly the Mainland side were back to defending goal-by-goal play with less than five minutes remaining.
In a desperate bid to secure victory, Tactix coach Marianne Delaney-Hoshek brought Australian import Kate Beveridge on to the court, hoping that the international shooter could provide a sense of calm for her side.
But a confident long shot from Silver Fern Te Paea Selby-Rickit saw the Steel secure the hard-fought win with confidence.
The Steel remain second on the ANZ Premiership ladder with 12 points, while the Tactix are third with nine.
The bottom-of-the-table Northern Stars will look to claim their first win of the season when they face the Magic tomorrow night.
The final round six clash will be played at the Magic home court of Tauranga's ASB Baypark Arena.