The starkly contrasting emotions of a local derby result were never more evident than with 12 minutes to go and Tigers leading the Saints 24-8.
Deciding that the game was already over, the first pockets of dejected Saints fans left their seats and trudged towards the exits.
Walking past a section of already delirious Tigers fans in the corner of the ground, they were greeted with a chorus of: "Oh when the Saints go marching home, oh when the Saints go marching home..."
It was a brutal send-off for a group of supporters who had just seen a seventh consecutive defeat by their most bitter rivals.
For the travelling Leicester contingent, however, things only got better as two more tries in the final 10 minutes gave them a 36-8 bonus-point victory to tell their grandchildren about.
They were in fantasy land by the final whistle after watching their side steadily control the first half before unleashing a four-try burst after the break.
Fly-half Toby Flood, clearly relishing the captain's role handed to him by director of rugby Richard Cockerill, had been perfect with the boot in the opening period to give his side a 12-3 lead.
And although Leicester could have easily scored a couple of tries on top, especially with Courtney Lawes in the sin-bin for a deliberate knock-on, Tigers were already looking the better side.
It took just 90 seconds for the visitors to extend their lead after the interval.
Manu Tuilagi was on the end of a 10-phase drive, which had Jordan Crane's name written all over it with two rampaging runs and some lovely soft hands at the crucial time.
Saints had to score next at 17-3 and they eventually did through Stephen Myler after Niall Morris has been yellow-carded for a deliberate knock-on.
But they only scored after Tigers had repelled their famed driving maul time and time again with some tremendously aggressive defence that rendered their most dangerous weapon impotent.
With 14 men, Tigers marched down the other end and Tuilagi added his second as he brushed aside the challenge of Tom May in midfield.
By the time Morris returned, Tigers were rampant.
Morris promptly made it 31-8 on 71 minutes after a build-up that contained some wonderful off-loading.
Smelling blood, and a bonus point, Tigers poured forward and got what they wanted just three minutes later as Mat Tait found himself one of a five-man overlap to complete the rout.
Franklin's Gardens was stunned. Before kick-off, this one had been almost impossible to call.
Saints went into the game after a four-game unbeaten run and there was talk before the match of not only of beating Leicester – but getting a home semi-final too. Sadly for the packed home crowd, this was men against boys.
Across the board, the visitors were superb and every decision they made seemed to be the right one. This was the performance Tigers supporters have been craving all season – and it came just when they needed it most.
Tom Croft was man-of-the-match for an astonishing showing that booked his place on the plane for the Lions tour in the first-class cabin – as long as the metalwork in his neck gets through the security checks, that is.
Flood and Ben Youngs ripped Saints' defensive line to shreds with flat and attacking passes, Anthony Allen was superb in midfield and two-try Tuilagi had his best game in a long while.
Tigers back-three were rock solid under the high ball, Geoff Parling and Ed Slater were immense in the second row, Crane was at his bullying best at No.8 and Julian Salvi cruelly exposed Saints' lack of a genuine openside to completely boss the breakdown.
Saints were also comprehensively out-coached. Cockerill and head coach Matt O'Connor stopped the home side's maul to kill off their most potent weapon, exposed the space in Saints' drift defence in open play and were clinically efficient turning turnover ball into scoring opportunities.
"I'm not sure we will ever beat this lot again," grumbled one Saints fan in the bar afterwards.
It was an incredible afternoon.