Never mind how long Saints have waited for a win against Tigers - how long have they waited for a win that was as comfortable as this?
Jim Mallinder's men hadn't beaten their bitter rivals since December, 2014, with seven long meetings having elapsed in that time.
Derby day had so often signalled pain for those of a Saints persuasion as Tigers continually held the upper hand.
And even when Northampton did over come Leicester twice in the same year, they had to do it the hard way.
Tom Wood's dramatic try helped 14-man Saints see off Tigers 21-20 in the Premiership play-off semi-final at Franklin's Gardens in May, 2014.
And seven months later, Saints, again down to 14 men on home turf, showed real character to overcome the old foe 23-19 in a regular-season showdown.
Those were the only two wins Saints had enjoyed against Leicester in a total of 19 meetings.
It was a sobering record and one that brought a large amount of misery.
So how sweet it was for Saints to not only beat Tigers on Saturday, but to put them away in some style.
There were no last-gasp heroics needed.
No nerve-jangling final stages.
Instead, Saints bossed the game pretty much from start to finish.
Luther Burrell's score was the least they deserved after coming flying out of the blocks, and Dylan Hartley added another before the break.
Tom Collins capped a sensational display with a score to match as he sidestepped Ben Youngs and dived over the line to seal the win.
Jonny May's eye-catching late try was barely any consolation for Tigers as the Gardens faithful celebrated a long overdue success with a chorus of 'who the hell are Leicester Tigers?'.
And what a success it was.
Saints were under huge pressure coming into the match, having been slaughtered by Saracens at Twickenham on the previous Saturday.
But, as Mallinder's men have done so often over the years, they pulled together, instilled a siege mentality in their dressing room and summoned up a showing saturated with spirit.
Led by Hartley, who produced a gargantuan display, and Courtney Lawes, who was even more outstanding then we've come to expect in recent times, Saints totally overwhelmed Tigers.
The only area of joy for the away side was the scrum, which they dominated all day.
But they couldn't use it as a platform to claim the points as Saints simply suffocated them in open play.
The home side had clearly learned from Bath, who won at Welford Road on the previous Sunday.
The west country side disrupted the lineout and used lightning kick-chase and smothering defence to stifle Tigers' creativity.
Their star-studded back line hardly got a sniff as Saints shut the door in their faces time and time again.
It was so different to Twickenham as the gaping holes were sewn up - and so was the match.
Almost every Saints player emerged with huge credit as character and class was shown in equal measure.
It resulted in a convincing success that gives the club a shot in the arm, an injection of confidence moving forward.
And now the challenge is to back it up.
Saints know they can't keep relying on big defeats to help them produce big victories.
Mallinder said this display was the standard his team must continue to reach this season.
The tough tests keep coming, with Bath, who have beaten both Tigers and Saracens so far, up next at the Gardens.
And if Saints can bring this level of performance again, they are capable of claiming another big victory.
But for now, it is time for those of a Northampton persuasion to sit back and enjoy some rare bragging rights.
How they rated...
Looked defensively secure and started a few attacks by gathering high balls and spotting space... 7
The Wales wing looked refreshed as he continually carried the ball into enemy territory, keeping Tigers on their toes throughout... 8
What a debut for the Australian centre, who added real grit and no shortage of class to the Saints midfield... 8
This man looked back to his bulldozing best as he put Tigers on the back foot and got the scoring started with a tidy try... 8
Was one of the few players to emerge with credit from Twickenham a week earlier and he was superb here, cutting Tigers apart to score a stunning try that sealed the win... 9
A characterful showing from the youngster, who bounced back from a really difficult display against Saracens with an accomplished performance here... 8
Like Mallinder, he didn't have the best day at Twickenham, but he was so much sharper here, buzzing around and refusing to give Tigers a second to breathe... 8
Was up against it in the scrum with Lions prop Dan Cole his opposite number, but put plenty of effort in around the park and helped Saints push Tigers back... 7
The skipper led from the front with a hugely physical display that was capped with a try. He also taught Leicester a lesson on lineout throwing... 9
Helped to set up Burrell's try with a composed pass, but was withdrawn at half-time after having a difficult half in the set piece as Ellis Genge got the better of the scrum battle... 6
Made some really key contributions for Saints, showing why the coaches chose to start him in this huge fixture... 8
Always adds a secure approach to the Saints second row and helped to marshal the troops in a typically assured showing... 7
COURTNEY LAWES - CHRON STAR MAN
Second row or back row, it doesn't matter to this man mountain, who was everywhere in another incredible, all-action display... 9
Gets through so much work week in, week out and this was a hugely satisfying afternoon for the flanker against his former club... 8
A great option at No.8, he adds plenty of power and desire and some big carries helped Saints to keep the intensity high... 8
Replacements (who played more than 20 minutes)
PAUL HILL (for Brookes 40)
Added plenty of fire and desire from the bench, with some strong carries, but Saints' scrum didn't function on this occasion... 6