The win - and the St Kilda Saints' 79-68 loss to Otago Boys' High School - meant the Bombers and Saints both finished the regular season with 11-4 records.
However, the Bombers finished on top thanks to a 2-1 head-to-head record against St Kilda this season.
The top-two sides will battle it out this weekend for an automatic place in the August 23 final. The loser of their qualifier will play the winner of the Otago Boys' and Falcons A quarterfinal next weekend for a spot in the decider.
The Bombers' win completed a remarkable regular season turnaround. Only 12 months ago the boys in green won just two games and finished dead last.
Now the squad heads into the playoffs on the back of two wins and some much needed momentum. New Zealand under-18 and Bombers point guard Richie Rodger (15 points) finally returned from a calf injury.
However, he has representative commitments the next fortnight and will don the Bombers uniform again only if they reach the final.
Bombers Cody Gillies continued his fine form and finished with 25 points, including a clutch three-pointer in the final minute to help the Bombers repel a late Magic rally.
Last year's MVP, Nuggets and Magic guard Micah Lepaio (38 points), was outstanding as he tried to lift his side into the playoffs.
Down 65-57 with a quarter to go, he drilled three consecutive long-range jumpers to keep his side within striking distance.
Lepaio's seven three-pointers raised memories of a meeting between the two sides last year, when he struck 11 times from beyond the arc.
With 54 seconds left and the Bombers leading 81-79, Gillies landed the dagger three-pointer, before Max Jablonski iced the game from the charity stripe.
The loss means the defending champion Magic finishes the regular season in fifth place and will play sixth-placed Varsity A this weekend to round out their seasons.
Sam King ensured Varsity (4-11) finished the regular season with a 105-96 win against the Falcons (5-8) with a game high 30 points. Magnus Holding (21 points), Ollie Smith (18) and Emerson Watson (15) also had strong performances in the win.
However, despite winning three of its last four games, Varsity was not able to recover from its dismal 0-8 start. Sam Timmins scored 26 points in Otago Boys' 79-68 win against the Saints.
The schoolboys won the game on the back of an outstanding first quarter as they outscored St Kilda 26-10.
With a healthy Timmins dominating inside, Otago Boys' will fancy its chances this weekend in the quarterfinal matchup with the Falcons, who limp into the playoffs with four straight losses.
By Robert van Royen.
