The home side held its nerve to seal a dramatic 46-44 win but it was the visitors who played the more enterprising netball.
The Perth-based side had spent two days getting to Invercargill and only arrived 24 hours before the match.
It was expected to fade in the second half but produced an electrifying third quarter, outscoring last year's minor semifinalist 15-8.
Spearheaded by a superb performance from Australian shooter Caitlin Bassett, the Fever took a three-goal lead into a frenetic final 15min.
A raucous crowd of about 2800 swung in behind the Steel with a deafening and united chorus as their side's hopes hung in the balance.
As if answering the crowd's call Megan Dehn produced a memorable pass.
Seemingly tumbling out of court she lobbed the ball over the defence to Daneka Wipiiti under the hoop, and Leana de Bruin, who was excellent in her first match back since having a baby late last year, poached a pass meant for Bassett.
Moments later she gave the slight 21-year-old a wee bump, just enough to tip her out of court.
The umpire missed the contact and the Steel moved the ball up court to draw level 42-42.
Having gained parity the Steel caught another break when Bassett was called for stepping right under the net.
It looked dubious from the sideline and Bassett gave a rueful glance at the official.
The Steel converted the opportunity and Te Huinga Reo Selby-Rickit helped clinch the win with a late deflection.
Fever coach Jane Searle said the Steel's stifling defence was the difference between the two sides but described some of the officiating as "interesting".
"There were a lot of penalty calls there that you had to just scratch you head with sometimes," Fever coach Jane Searle.
"But the bottom line is we need to adjust to those calls. We certainly gave ourselves every chance of winning, and put ourselves into a winning position but just needed to go on with it."
Steel coach Robyn Broughton was satisfied with her side's first outing in the ANZ Championship.
The Steel showed a lot of character to claw its way back after a poor third quarter and in the end the Steel's experience shone threw.
"We put ourselves under huge pressure but I thought they did a good job to get it back," Broughton said.
The defence picked up some good ball and we got a couple of really good turnovers towards the end.
"Patience was the key thing," she added.
Fever's midcourt duo of Madison Browe and Shae Bolton outplayed their opposites, and Emma Beckett, who at the grand old age of 25 is the Fever's oldest player, made some nice touches when she came on partway through the third quarter.
Towering goal defence Susan Fuhrmann gave Daneka Wipiiti a rough ride, cutting in front of the shooter and climbing high to steal valuable ball.
Bassett produced an almost flawless game landing 34 of her 35 attempts.
For the Steel, de Bruin was a standout and Dehn showed glimpses of the sort of form which catapulted her into the World Sevens team last year.
Wipiiti fell awkwardly towards the end of the match and needed some help leaving the court.
The state of her injury was unknown last night.
Steel 46 (Daneka Wipiiti 28 from 33, Megan Dehn 18/22) Fever 44 (Caitlin Bassett 34/35, Leah Shoard 10/15) Quarter 12-11, halftime 24-20, third quarter 32-35.
