It was a Tremmell Darden-inspired run during the middle stages of the third term that set-up the victory, with the Dragons extending their 11-point half-time advantage to a match-winning 18 at the final break.
Darden hit 21 of his career-best 31 points during that quarter to help his side take control of the contest and there were no final-term heroics from the Tigers as the Dragons sealed the three-games-to-two result in the best-of-five Grand Final series and became the first team in NBL history to go from wooden-spooner to Championship winner in the space of 12 months.
While Darden was the star of the show in the deciding match of the series, fellow American Donta Smith played just as big a role in the victory.
Smith narrowly missed a triple-double with 21 points, 10 rebounds and seven assists and also became the first import to win the Larry Sengstock Medal since the talented Chris Williams was adjudged the best player of the Grand Final series in 2003.
Dragons skipper Mark Worthington and young swingman Joe Ingles contributed nine points apiece in the victory, while Mika Vukona and Matt Burston shot eight each.
For the Tigers, Ebi Ere (16 points), David Barlow (16) and Chris Anstey (12) battled hard, but the Dragons were hungrier for the victory - they won the rebound count 47-33 - and shot the ball at a magnificent 53 percent shooting clip throughout.
It was a sixth NBL Championship for Dragons coach Brian Goorjian and he said it was the sweetest.
"The older you get you understand how important they are," he said.
"And in this one we picked ourselves up off the canvas after Game Four when everybody thought we were down and out."
"We didn't win a road game all series, but we won the Championship."
Tigers coach Al Westover was bitterly disappointed after the game and said his team wasn't as sharp as they needed to be to win a series decider.
"We didn't get anything going inside with our offence, we had a lot of turnovers in the first half and we got out-rebounded," Westover said.
"They killed us on the break and got to the line twice as often, so pretty much in every area we got beat."
Nathan Crosswell (11 points, four assists) and Ere found their range early on as the Tigers edged out to a seven-point lead midway through the first term, but it didn't take long for the Dragons to come to terms with the zone defence their opponents were playing.
Smith threw down a big dunk on the fast break and then nailed a huge three from the top of the arc right on the quarter-time buzzer as the Dragons ended the stanza with an 18-7 run to take a four-point (28-24) lead into the first break.
Things started to hot up in the second term as Smith scored four consecutive baskets to help give the Dragons a double-digit lead and the Tigers began to struggle from the field.
The Tigers could only manage six field goals in the second term and with the Dragons leading the rebound count 22-17, the home side enjoyed a healthy 11-point (52-41) buffer at the half.
Darden was playing the perfect support role to Smith in the opening half and he provided the Dragons' first five points of the third term as the hosts extended their advantage to 13.
Tommy Greer (six points, four rebounds) connected from beyond the arc and hit a long-two to bring the Tigers back within eight, but Darden nailed back-to-back triples as the Dragons went on a 12-2 run to break out to a 24-point lead.
A triple from Anstey and a Luke Kendall (nine points, three assists) heave from half-court on the three-quarter-time buzzer brought the Tigers back within 18 (82-64) with 12 minutes remaining.
Another three from Kendall helped reduce the Tigers' deficit to 16 early in the final term, but they could get no closer as Smith, Ingles and Worthington stepped up over the final stages to allow the Dragons' celebrations to begin.
South Dragons 102 (Darden 31, Smith 21, Worthington 9)
Melbourne Tigers 81 (Ere 16, Barlow 16, Anstey 12)