A record crowd for the competition watched the two sides slug it out at Welford Road and while a Howard Packman try reignited the visitors' hopes in the second half, Leicester’s two earlier scores in a Saints dominated opening 40 were what ultimately counted on the scoreboard.
Owen Williams sent an early penalty to the corner and though the Saints initially did well to stem the lineout drive, Sebastian De Chaves crashed through the fringe defence for the first points of the afternoon.
Will Hooley responded with a penalty as the Saints worked their way into the game but having bossed a 20-minute period in enemy territory, there were to be just the three points as reward.
Instead it was the hosts who crossed again, Jack Roberts’ scything break eventually finished off by Laurence Pearce in a rare loose spell of the game.
There was almost an immediate repost, Teimana Harrison wrestling his way brilliantly to the line but agonisingly short with an outstretched arm before fumbling.
It wasn’t to be the last chance of the half either, a huge maul held up over the whitewash before Dom Waldouck’s driven effort was chalked off for blocking.
With an advantage in the bag, Saints opted to scrum and while further penalties followed, a knock on deep into added time rendered their efforts fruitless.
That in mind, it was a tad ironic that having had to repel a string of Tigers attacks and a couple of five-metre lineouts that the Saints scored first after the break.
Sam Olver’s penalty took them into the 22 for the first time in the half and it was his superb dink that Howard Packman latched onto in the left corner to make it a one score game.
Unfortunately, play moved quickly back to the other end of the park and when Williams knocked over a penalty, it looked like it would be enough for the hosts.
That's the way it would prove, despite one final assault on the Tigers line and the Saints made the short journey home empty-handed.
The Saints will now need to beat Wasps at Franklin's Gardens in seven days time and keep an eye on Cardiff's results if they wish to progress. Tickets for the crunch class are available HERE.
5mins TIGS Try De Chaves Con WIlliams 7-0
21mins SAINTS Pen Hooley 7-3
32mins TIGS Try Pearce Con Williams 14-3
HALF-TIME TIGERS 14 SAINTS 3
76mins TIGS Pen Williams 17-8
FULL-TIME TIGERS 17 SAINTS 8
TIGERS Bell; Morris, Catchpole, Roberts, Thompstone; Williams, Harrison (capt); Rizzo, Thacker, Balmain, Peterson, De Chaves, Gibson, Barbieri, Pearce
Reps: Briggs, Brugnara, Mulipola, Whetton, Beckett, Mele, Smith, Hepetema
SAINTS Collins; Elliott, Waldouck, Stephenson, Packman; Hooley, Hodgson; E Waller, Williams, Denman, Ryder, Woolford, Dowson (capt), Harrison, Dolan
Reps: Marshall, Hobbs-Awoyemi, Parkins, Onojaife, Nutley, A Day, Olver, Hutchinson
REFEREE Nigel Owens