Will Neighbour led the GB scoring finishing with a 24-14 double-double in 33 minutes of action, with Jack Stannard and Ovie Soko each finishing with 13 points, plus four and seven rebounds respectively.
Andrew Lawrence added ten points, and ten of the 11 players used by coach Tim Lewis got on the scoresheet.
Lewis' team out-rebounded Norway 39-16, and outscored them from all areas of the court - finishing with an impressive 62 percent from two point land, 53 percent from outside the arc 87.5 percent from the foul line.
The GB coach couldn't hide his delight at the victory: "Like I said yesterday, the team is really starting to believe in themselves" he said.
"It would be wrong to single out any individual as it was a great team effort. You could look at Will's stats or the great contribution from Jack Stannard, but ultimately it came down to unselfish play from all of the team. We finally have a group of players who know that if they work together they will be successful and get the wins.
"Offensively we were excellent, but it was our defence that really stood out. We knocked down passes, got the deflections and out-rebounded them. That was some of the best basketball I've seen for a long time."
GB started strongly as four points Will Neighbour launched an 11-0 run to give them a lead they would never relinquish.
Lawrence, Van Oostrum and Soko took the lead to 10-0 before a single Myles Hesson free-throw completed the tear.
Roy Nwachukwu eventually put Norway on the scoreboard with a single foul shot, and that launched an 11-2 run for the Norweigans before GB finished the period strongly as Stannard hit four straight free-throws to send them into the first break 17-11 ahead.
That run was extended to 11-0 as Neighbour again opened the scoring before Stannard drained a trey and Ali MacKay converted a lay-up.
Norway never managed to get that lead into single figures during the rest of the period, with Neighbour continuing to terrorise their defence on his way to 13 points for the half, and he sunk a trey off Lawrence's assist with 12 seconds remaining to send GB into the locker room with a 46-28 half-time lead.
Unsurprisingly it was Neighbour who opened the second half scoring, and back-to-back Soko three-pointers followed by another Neighbour basket saw GB's lead balloon to 56-28 with just over three minutes gone.
Lawrence got in on the action by scoring from the Land of Plenty, and a pair of Hesson free-throws sent GB into the final break with an unassailable 68-32 lead.
Once again Neighbour opened the scoring in the fourth period, and Lewis was able to run his bench during the fourth period and it was Raheem May-Thompson wrapped up the scoring as GB took another step towards the semi-final.
GB face Poland on Tuesday evening knowing that a victory is a must to retain their promotion hopes.
