Newcastle conceded a needless penalty in the first minute when David Walder ran it out of his 22 instead of kicking for touch – and then his kick did go out on the full.
Northampton surged upfield to force a penalty and Shane Drahm kicked the goal to give the Saints just the start they wanted and the Falcons had only themselves to blame.
Tom May knocked over a snap drop-goal in the fifth minute after two powerful drives by Epi Taione and a superb pick up by Andy Long to set up the chance.
Wylie Human was lucky to get away with deliberately playing the ball on the ground and throwing the ball into touch after being tackled by Mike Stephenson.
Newcastle drove Northampton back and it seemed Jamie Noon would break through but the Saints were offside and Matt Burke put Newcastle 6-3 ahead.
Then Bruce Reihana threw out a pass well forward but referee Geraint Ashton-Jones and his touch judges apparently could not see it and John Clarke scored in the corner and Drahm converted before Burke kicked a penalty for Newcastle only for Drahm to make it 13-9 with a penalty for hands in the ruck.
Newcastle were making so many errors and conceding so many turnovers they were lucky to be just 13-9 down and they rode their luck to be just 13-12 down at half-time with Burke's third penalty after 36 minutes.
The Falcons moved back into the lead with a Walder drop-goal early in the second half after the Saints made mess of a 22 drop-out and when Chris Budgeon strayed offside in the 48th minute Burke made it 18-13.
But then the Saints put in a great driving maul to gain a penalty which Drahm kicked to make it 18-16.
In a penalty-strewn match Northampton obstructed at the ruck and Burke kicked his fifth penalty before the introduction of Colin Charvis, scorer of four tries against Japan on Friday, made an immediate difference.
The Newcastle pack drove into the Saints' 22 and Walder kicked the penalty when Northampton were offside and then kicked his second drop-goal in the 71st minute.
For Newcastle Falcons:Pens: Burke 5, WalderDrops: May, Walder 2
For Northampton Saints:Try: ClarkeCons: DrahmPens: Drahm 3