In an action-packed contest, in which the lead changed hands three times, it appeared a draw was looming after an 82nd-minute penalty from striker Jamie Maclaren pulled the Roar level.
But Danish import Nordstrand popped up just two minutes later to drive a dagger through Brisbane's hearts, standing his ground and firing from close range after an aerial contest with goalkeeper Michael Theo, who was yellow-carded for protesting the incident afterwards.
It was no less than what the Jets deserved after delivering one of the biggest shocks of the A-League season so far.
It is the Roar's first defeat in nearly 12 months at home, and came after Newcastle also smashed them 4-0 back in round two at McDonald Jones Stadium.
Tommy Oar's first goal for Brisbane in more than seven years opened the scores after just 15 minutes, and they looked comfortable 1-0 up.
The Jets struck back right on the stroke of half-time, as Andrew Hoole dribbled his way through a flat-footed Roar defence and found the top corner with a rocket from 20 metres, stunning the crowd of 14,470.
Then in the 72nd minute, Newcastle's other winger Andrew Nabbout made it 2-1, heading in a cross from fullback Jason Hoffman that caught a slight deflection off Jade North's head along the way.
Brisbane thought they had done enough to salvage at least a point when Maclaren scored his seventh goal of the season from the spot, after Nigel Boogaard brought down Jack Hingert in the penalty box with a clumsy challenge.
However, Nordstrand had the final say, pushing the Jets back into the top six and leaving the Roar in danger of losing touch with breakaway ladder leaders Sydney FC.
The Roar next meet second-placed Melbourne Victory next week at AAMI Park, while Newcastle are at home to Perth Glory.
