This has been the season when Saints have seen their impressive stranglehold over certain sides released.
It has been the campaign when reputation has counted for nothing, with plucky underdogs making a mockery of pre-match odds.
The bookies have been left red-faced as Saints have stuttered, losing to all three of the league’s current bottom three teams on the road.
Worcester Warriors, London Irish and Newcastle Falcons may only have 10 wins between them during this campaign, but all of them have beaten Saints.
And that will be a source of pain for Jim Mallinder’s men, who have come so close in all of those games but failed to get over the line when it mattered.
In the past, Saints’ standing would have weighed heavy on the shoulders of those sides.
They may have gone ahead, but they wouldn’t have won.
They would have played in patches, but they would have been punished for not being able to play to that level for the full 80 minutes.
But this season has been different.
This time, Saints have been the ones failing to play to their potential for the entirety of matches.
Opposition teams have ripped up the history books with alarming regularity.
Worcester had only beaten Northampton in one of nine meetings before the two teams met at Sixways on the opening night of the new season.
But the Warriors landed a late drop goal to seal a dramatic, but deserved 13-12 victory.
London Irish had lost their previous six games against Saints before upsetting Mallinder’s men on Boxing Day.
As with Worcester, Irish held their nerve late on to snatch the points needed for victory, earning the win via a penalty try and a Shane Geraghty conversion.
Newcastle already had the points in the bag as they held out against Saints on Sunday, ending a run of 12 successive defeats at the hands of Northampton in the process.
Add to that Wasps’ first win at Franklin’s Gardens since November 2005 when they stormed to a 24-11 success last month, and this has been a season which has seen records tumble.
Saints have been so dominant against those teams in the past, but not any more.
This time, their typically strong mentality and refusal to lose has deserted them in certain situations.
It looked like it had returned at Harlequins a couple of weeks ago, as Ben Foden’s late score ensured Saints made it six successive wins against Conor O’Shea’s side.
And when London Irish were routed 35-7 last week, belief was high that the top four bid was firmly back on track, with Saints just two points off fourth place.
But the defeat at Newcastle was another setback.
Saints had not won three successive league games during this campaign, and they still haven’t.
Andy Goode’s kicking masterclass saw to that, with the old-stager showing those younger than him how it’s done.
So metronomic was his kicking that you felt he could put the tee on top of the burger van in the corner of Kingston Park and still bisect the posts.
He was that Goode.
Yet despite the veteran’s classy showing and a suffocating Falcons display, Saints could still have snatched it late on.
And that will be the overriding frustration of the season so far.
They know they have the quality, and they produce it in patches, but they rarely string it together for a full game.
They conceded 20 points before the break at Kingston Park, and you just can’t afford to give teams a headstart like that.
Saints need to start learning that lesson now, with only nine games of the regular season to go.
If they can do that, they can put defeats like the ones at Worcester, London irish and Newcastle down to bad days at the office.
If they can’t, they will continue to have fans worrying that it is a sign of a wider malaise.
How they rated...
Handled the high ball well in tricky conditions and constantly tried to get Saints on the front foot, eventually moving to the wing... 7
The winger put in a fine display against London Irish on the previous weekend, but he couldn’t really get in the game this time... 5
Had been in fine form during the previous two weeks and showed that belief here with some strong running, but occasionally failed to find men outside him... 6
A tough day for the youngster, especially when he moved to full-back, as Newcastle put the pressure on... 5
Was withdrawn during the second half, but had looked strong up to then, trying to carry the fight to the Falcons... 6
Wasn’t able to control the game as he would have liked as opposite number Goode took the plaudits for pulling the strings... 5
Saints’ best player, the skipper was always trying to make things happen and his two tries were just reward... 8
Couldn’t really get the upper hand in the scrum, but battled hard against a determined Newcastle pack... 6
Tried to add plenty of energy around the field as usual, but the Falcons met the hooker and his team-mates at every turn... 6
Was jeered by a couple of home fans when his name was read out and he proceeded to put in a powerful display... 7
Struggled to adjust the conditions early on, but bounced back to put in a solid enough showing... 6
Rarely has a bad game and he did okay here, putting in plenty of graft and trying to control Saints’ forward effort... 6
A really hardworking display from the flanker, who got Saints up and running with their first try... 7
Never lets the team down and was no different here as he put in another strong performance... 7
Wasn’t able to have too much influence on the game and was forced off with a head knock 15 minutes into the second half... 6
Replacements (who played more than 20 minutes)
JJ HANRAHAN (for Myler 49)
Injected a bit of extra tempo when he came on and played a key role in Saints’ second try... 7
TEIMANA HARRISON (for Dickinson 56)
Like Hanrahan, he brought extra energy to proceedings and helped turn the tables on Newcastle... 6
CHRON STAR MAN: Andy Goode (Newcastle Falcons)