The home side snuffed out the Steel's meek attacking forays with consummate ease and pulled away in the last quarter to win 51-36.
The 15-goal drubbing is the third time this season the Steel has lost by 15 goals or more and it was its ninth consecutive loss on Australian soil.
A place in the playoffs is a distant dream unless the Steel can suddenly discover some chemistry on attack.
You have to feel for Steel goal keep Leana de Bruin. The Silver Ferns defender is in excellent form but every time she comes up with an amazing play to win the ball for her side, it is squandered.
The lack of finishing must be getting to de Bruin, because she described the side as "soft".
"I just think we are soft," de Bruin told Sky Sport.
"We come over here and we know the umpiring is a little bit different, but I just think we need to toughen up and grab the ball and own it."
De Bruin said the Steel's strategy was to take the pace out of the game and be patient with possession.
"We know they are very fast all over the court so we needed to slow them down and, hopefully, stop the biff into Romelda [Aiken]. Credit to the girls, I think they did that pretty well."
Defensively, for the most part, the Steel did a wonderful job on Aiken. But paying all that attention to the Jamaican international meant there was plenty of opportunity for Natalie Medhurst to make her mark.
The classy goal attack took up the slack, scoring 22 of her 25 attempts. You can never shut Aiken down completely and she scored 29 from 35.
Steel shooter Daneka Wipiiti had a reasonable match, scoring 22 from 27. But former Silver Fern Paula Griffin had another disappointing match with 14 from 21. She needs to get more involved off the ball and work harder to get into space.
The Steel dominated the first 10mins. The visitors controlled the tempo and the zone defence it was employing was giving the Firebirds pause for thought.
Aiken was forced deep in the circle, thanks to some rigid defence. She is lethal under the post but not as comfortable when more than a couple of metres from the hoop. Some fantastic passing from Liana Leota and great positioning from Wipiiti saw the Steel carve out a three-goal lead.
But whether it is a lack of fitness or of mental toughness, the Steel faded and it is becoming a habit.
The home side posted five unanswered goals to take a 13-11 lead into the break and quickly regained their rhythm, adding four quick goals to stretch the margin to five.
Defender Amy Steel was getting the better of Griffin and goal keep Laura Geitz was impressive. And when Medhurst and Aiken started to find more space at the other end, the Firebirds were able to outscore the Steel 13-7 in what proved to be the decisive quarter.
Steel coach Robyn Broughton made one change, bringing on Erika Burgess for the tiring Sheryl Scanlan.
The Steel kept fighting and traded goals in an improved quarter. De Bruin was a powerhouse at the back, getting around her opponents to snatch intercepts and deflect the ball. Most of the extra ball she generated was wasted, though. The Steel just could not make any inroads into the Firebirds' eight-goal lead, coughing up possession at crucial times.
The Firebirds played two matches in the last round and the Steel should have expected to finish stronger than its opponent, having played just once last week.
But it was the Steel that faded, mustering a pathetic haul of just six goals from the 15min period.
In other matches, the Adelaide Thunderbirds beat the Central Pulse 51-41 in Adelaide, and the Northern Mystics downed the Melbourne Vixens 56-54 in Auckland.
FIREBIRDS v STEEL
- The scores
• Queensland Firebirds - 51
Romelda Aiken 29 from 35, Natalie Medhurst 22/25.
• Southern Steel - 36
Daneka Wipiiti 22/27, Paula Griffin 14/21.
• Quarter 13-11, halftime 26-18, third quarter 38-30.
