They exhibited a defensive attitude that reminded of some of their epic wins last year, as they swarmed in packs to rattle the usually efficient Storm machine.
Debutant Patrick Herbert caught the eye at right centre, while Tohu Harris stood up to the challenge of leading such an inexperienced team. Peta Hiku impressed as a stand-in fullback while Ken Maumalo topped 200 running metres.
The Warriors backline was dramatically transformed, with the absence of Roger Tuivasa-Sheck, Blake Green and Solomone Kata, but it didn't show.
After the typically emotional pre-game Anzac ceremony, the Warriors rose to the occasion instead of being dazzled by it.
Chanel Harris-Tavita converted an early penalty, before Adam Blair rolled back the years with a strong try, running off a clever Harris pass.
The Auckland team had a chance to extend their lead soon afterwards, but Blake Ayshford shelled an inside ball with the line open.
But the most impressive aspect of the first half was their defence, as they repelled multiple Storm attacks.
Melbourne needed a touch of luck to get going, with Cameron Munster left alone to reel in Josh Addo-Carr's volleyball style tap back from a bomb.
The Storm were under some pressure, but it looked to be released early in the second half as Jahrome Hughes crossed from a precise Cameron Smith grubber.
But the Warriors responded, with Maumalo set up by a brilliant Hiku pass. The visitors were hanging in well and defending courageously, though penalties and errors were starting to take a toll.
The Storm dominated possession and territory, and the Warriors' kicking game started to go awry, but the home side couldn't break through, before Munster's late, late penalty goal was followed by an even later drop goal from Croft.
In the earlier game on Thursday, the Roosters prevailed over the Dragons 20-10 in a thriller at the Sydney Cricket Ground.
Storm 13 (C Munster, J Hughes tries; C Munster con, pen, B Croft drop goal)
Warriors 12 (A Blair, K Maumalo tries; C Harris-Tavita 2 goals)
Halftime: 8-4
