There was certainly good reason for Saints to love thy neighbour on Saturday.
Because, thanks to east midlands rivals, old and new, they took a giant step towards securing an invitation to their own party next month.
Traditional foes Leicester Tigers crushed Cardiff Blues 43-9 at the Arms Park, meaning Saints needed a minimum of two tries and a win against this region’s newest residents, Wasps, to progress to the LV= Cup semi-finals.
And after a first-half full of fight, Dai Young’s side headed off tamely into the night as Jim Mallinder’s men celebrated a comprehensive bonus-point triumph.
It means Saints are now just one win away from attending the Franklin’s Gardens final on March 22.
And how dearly they would love to do that.
The Anglo-Welsh competition might not carry the glamour of an England-Wales battle in the Six Nations, but it is something valued by Saints.
They have now reached the semi-finals in four of the past six seasons, claiming the title in 2010.
That good record is not coincidence.
It has come from affection for the tournament and an ability to field a strong side while a plethora of first-team regulars are away or rested.
That was the case once again on Saturday, and once again those who came into the side stepped up.
From Ahsee Tuala, the new Samoan full-back with a shirt size equal to that of prop Alex Corbisiero, to Sam Olver, the young fly-half, Saints showcased their strength in depth.
They took their chances when they came and got back on track after back-to-back defeats.
And that was vital not only for their LV= Cup hopes, but also their Aviva Premiership ambitions.
The league action returns on Friday night and Saints sit top of the table, having also progressed to the knock-out stages in the other two competitions they have entered.
Success breeds success and the fact Saints will still be in the hunt for a treble come the middle of March can only be good for the club.
Two blank weeks during that month can do as much harm as good and Mallinder will be desperate for his men to start building consistency.
They managed it last year, winning 13 games on the spin between December and March.
If they can get on a good run again, more memorable achievements like the previous campaign’s double beckon.
And thanks to their nearest and not quite dearest, Leicester and Wasps, one of those achievements could be winning a trophy on home turf.
How they rated...
A dream debut for the Samoan, who took just eight minutes to open his Saints account and who looked assured throughout... 8
So sharp as usual, eating up ground and continually causing problems for the Wasps defence... 7
Full of fire and desire in attack and defence, the centre, who will join London Irish this summer, looks determined to leave with a trophy... 7
Clever work to set up Tuala’s try and a typically lively display from the centre, who was an important figure... 7
Showed great awareness to latch onto Foutali’i’s excellent chip ahead and was a threat all day... 7
A really confident display from the young kicker, who looks to have learned from Stephen Myler in the assured manner in which he plays the game... 7
KAHN FOTUALI’I - CHRON STAR MAN
Such a class act, everything goes through the Samoan, who deservedly etched his name on the scoresheet after producing a fine assist for Elliott... 8
Was forced off after just 27 minutes with an injury that Saints are hoping is not too serious. No time to make an impact... 6
His performances during the past couple of weeks have been impressive and he is certainly one to watch... 7
Another strong display from the tighthead, who shrugged off an early knock that threatened to curtail his game... 7
Produced a warrior-like display at Leicester a week earlier and was at it again here, showing the merits of his signing... 7
Saints will be delighted to have the beanpole lock back as he adds a real presence to second row proceedings... 7
The captain led by example once again, competing for everything and giving up on nothing... 8
More tenacious work from the flanker as he continues to stake his claim for a starting spot when the Premiership action returns on Friday night... 7
Back in his favoured role at No.8 after playing as a lock for a number of weeks, and looked comfortable... 7
Replacements (who played more than 20 minutes)
ETHAN WALLER (for Corbisiero 27)
Was forced into action earlier than expected and showed his determination to help Saints get on top of a gritty Wasps side... 6
MIKE HAYWOOD (for Williams 54)
Tidied up a couple of scrappy breakdowns and will be glad of the game time with big league battles ahead... 6
ALEX WOOLFORD (for Craig 54)
The lofty lock enjoys these LV= Cup weeks and he can pleased with his efforts during the past two games... 6
SALESI MA’AFU (for Denman 57)
Back in action after a week’s rest and didn’t have to battle too hard as Saints were already in cruise control... 6
BEN NUTLEY (for Harrison 57)
Has seen Harrison get the nod in the battle for back row places and will be keen to stake his claim, but this game was over as a contest when he came on... 6
ALEX DAY (for Fotuali’i 59)
Did well in a cameo at Leicester a week earlier and looked composed again here as Saints kept Wasps at arm’s length late on... 6
GEORGE PISI (for Stephenson 59)
Added to the Polynesian flavour on the Gardens pitch and did some good work in defence as Saints kept Wasps out... 6