The Magic will battle it out with the Northern Mystics in Auckland next week for the remaining spot in the title decider against the Melbourne Vixens.
The showdown will be a repeat of last year's preliminary final. On that occasion, the Mystics edged out the Magic by a goal to play the Firebirds in the grand final.
The Magic may have been 17 goals better than the Thunderbirds two weeks ago, but last night's rematch was always going to be a much tighter clash.
The Adelaide side seethed privately that they were undone by the umpiring during that match - a tough claim when they lost by so much.
But last night they looked more comfortable with having one New Zealand and one Australian umpire officiating the proceedings, as they returned to their more confrontational style of defence.
The Magic had the visitors rattled early on, with the Thunderbirds coughing up the ball on their first possession, Casey Williams proving the spoiler. With suffocating through-court defence, there were more turnovers to follow for the Magic, as the midcourt worked hard to set up good ball for Williams and de Bruin at the back.
Irene van Dyk and Julianna Naoupu ensured the Magic made the most of their dominance in possession, shooting at 100 per cent for the first spell, which saw the home side take what appeared a commanding 15-7 lead at the first break.
But the momentum swung back in the second period, as the Thunderbirds piled the pressure on and the Magic attack end fell to pieces. Some cynical transition defence from the visitors didn't help the Magic's cause, as the home side's progress through court was stalled.
The Thunderbirds levelled the score at 21-all with five minutes of the period remaining, before taking a 26-23 lead at halftime.
The Thunderbirds maintained their hold on the match, taking a 39-38 lead heading in to the final turn. But Shadrock's intercept four minutes from time gave the Magic the opportunity to level the score at 47-all.
Then the umpires finally cracked down on the Thunderbirds' persistent offending in the final five minutes.APN News & Media