The Thunder 14.22 (106) defeated the Rams 15.8 (98) in the first of the final day's second division double-header at MC Labour Park in Carlton to finish the carnival with two wins and one loss against the red-hot Queensland.
Despite registering six consecutive majors - from late in the second term through to early in the third quarter - NSW/ACT was unable to chalk up its first win of this year's championships.
It capped off a disappointing finish for the combine, the 2003 second division title winner having now won just one game in the past two Under 18 Championships including this one.
The dazzling Nathan Djerrkura was outstanding for the Territory. He finished the match with 25 touches, 10 marks and three goals in a highly entertaining performance. His ability to baulk, evade and take on opponents was testimony to the Northern Territory football flair.
Josh Cubillo, Cyril Rioli and Daniel Cadona were also key players for the Thunder with the trio racking up more than 70 disposals between them.
Rams captain Craig Bird was once again a key player for his side, winning 26 possessions, while Myles Aalbers was prominent up forward with four goals. Ben Woods also bagged three majors.
NSW/ACT kicked the opening goal of the match via Evan Duryea, as the Territory peppered the sticks early, but to no avail. The Thunder had five behinds on the board, before Djerrkura kicked two gems on the run. By quarter-time, the Thunder had four goals to two and an 18-point lead.
The Territory jumped out to a 26-point advantage early in the second term, but when NSW/ACT hit back with three in a row - including two in succession from Nick Paine -the Rams trailed by just eight points at the long break.
NSW/ACT continued its fightback early in the second half, when it landed the opening three goals of the third quarter. And when Woods booted his third, the Rams had opened up an eight-point lead.
But when Calma-Holt bobbed up with two in two minutes, the Territory was back in front and remained so for the rest of the quarter. Entering the final stanza, the Thunder led by 15 points.
NSW/ACT put up a fight in the final term, reducing the deficit to just three points, but when Charlie Sharples kicked truly just minutes before the final siren, the Thunder held on for victory.
NORTHERN TERRITORY: 4.6 7.12 12.19 14.22 (106)
NEW SOUTH WALES/AUSTRALIAN CAPITAL TERRITORY: 2.0 7.4 12.4 15.8 (98)
GOALS - Northern Territory: Djerrkura 3, Calma-Holt 2, C.Rioli 2, Beugelaar, Campbell, Cubillo, Fittock, S.Rioli, Sharples, Wonaeamirri
NSW/ACT: Aalbers 4, Woods 3, McIntyre 2, Paine 2, Bird, Duryea, Stroobants, Wilsen
BEST - Northern Territory: Djerrkura, Cubillo, C.Rioli, Cadona, Wonaeamirri, Calma-Holt
NSW/ACT: Aalbers, Bird, McIntyre, Paine, Wilsen, Woods
Umpires: Pattinson, Tuckett, Ritchie/Medlin (1/2 each)
MC Labour Park, Carlton