The hosts trailed 21-7 at the interval despite getting off to the ideal start, leading inside six minutes.
Sustained red-zone pressure was rewarded with a try from a line-out strike play as Harrison Obatoyinbo darted through a midfield hole, coming infield from his left wing to dot down.
Brett Connon added the extras from out on the right but the sides were level on 12 minutes when Saints prop Luke Green scored from a close-range pick and go – Anthony Belleau converting.
Northampton nudged in front when scrum-half Tom James dummied and went himself for a converted try from the base of a ruck five metres out, and they had their third before the half-hour.
With no TMO it took a lengthy consultation between referee Hamish Grant and assistant Hamish Smales to unpick what had happened amid a heap of bodies in the right corner, but the outcome was a try for open-side Charlie Ulcoq and a third conversion from Belleau.
That left the visitors 14 points up at the break – the Red Bulls turning to their bench for inspiration as George Bolam and Max Clark emerged for the second half.
Northampton continued their dominance of the scoreboard, however, chalking up their four-try bonus point four minutes into the second half when the ball was worked right for centre Toby Thame to crash over.
The East Midlanders had a further score pulled back by the officials when full-back James Martin was judged to have strayed offside from a chip over the defensive line, but there was no stopping Thame on 52 minutes when the centre scampered in for his second of the night.
The Red Bulls showed some spirit and went close before the hour mark when replacement centre Max Clark hit a hard line from the back of a maul – his side having kicked a penalty to the left corner.
Clark was again to the fore when his line-break almost freed Tom Christie for a try – the attempted scoring pass going to floor – but the visitors were having no such problems converting their chances as replacement George Hendy rounded off a 60-metre attack for try number six.
Newcastle found their scoring touch on 72 minutes when Richard Palframan crashed over from a pick and go down the left – his side having kicked a penalty to the corner.
Connon added the extras, but Northampton crossed again three minutes from time when England wing Ollie Sleightholme raced in.
There was still time for one late consolation score, with repeated red-zone penalties seeing Ollie Fletcher scoring in the left corner four minutes into added time.
Newcastle Red Bulls: 15 Elliott Obatoyinbo, 14 Oli Spencer, 13 Rhys Beeckmans, 12 Cameron Hutchison (Max Clark, 40), 11 Harrison Obatoyinbo (Ethan Grayson, 27), 10 Brett Connon, 9 James Elliott (Joe Davis, 53); 1 Micky Rewcastle (Adam Brocklebank, 48), 2 George McGuigan (captain, Ollie Fletcher, 61), 3 Murray McCallum (Richard Palframan, 48), 4 Jamie Hodgson (Tim Cardall, 57), 5 Oscar Usher, 6 Adam Scott (George Bolam, 40), 7 Tom Christie, 8 Reuben Parsons.
Scorers - Tries: Harrison Obatoyinbo, Richard Palframan, Ollie Fletcher. Conversions: Brett Connon 3.
Northampton Saints: 15 James Martin (George Hendy, 58), 14 Ollie Sleightholme, 13 Tom Litchfield, 12 Toby Thame, 11 Amena Caqusau, 10 Anthony Belleau, 9 Tom James (Archie McParland, 62); 1 Tom West (Joe Cowell, 53), 2 Robbie Smith (Craig Wright, 53), 3 Luke Green (Cleopas Kundiona, 53), 4 Ed Prowse (James Bennett, 40), 5 Chunya Munga (captain), 6 Archie Benson, 7 Charlie Ulcoq (Jack Lewis, 52), 8 Sam Graham.
Scorers - Tries: Luke Green, Tom James, Charlie Ulcoq, Toby Thame 2, George Hendy, Ollie Sleightholme. Conversions: Anthony Belleau 7.
Referee: Hamish Grant. Attendance: 5,501.