A much-changed Saints side produced a spirited display at Welford Road, but it wasn’t enough to deny Leicester the win they needed to reach the Aviva Premiership play-offs.
Jim Mallinder made 12 alterations to the team which secured top spot with a 46-0 victory against London Welsh last Saturday.
And although the away side battled bravely, Tigers’ experience eventually told as they secured a 22-14 triumph that earned them third-place and a semi-final at Bath.
Saints, who were 9-8 up at half-time thanks to James Wilson’s trio of penalties, will face Saracens at Franklin’s Gardens in the final four next Saturday.
Mallinder rested the majority of his key men in anticipation of that game, with the likes of Stephen Myler, Samu Manoa and Courtney Lawes not involved at Welford Road.
But Saints, who have still not won at Leicester since 2007, still managed to put up a real fight, with their intentions clear from the off.
Sam Dickinson and Salesi Ma’afu led the way with bone-crunching hits, as Leicester, roared on by deafening cries from the home fans, knocked loudly on the door.
Freddie Burns used a penalty to put his team in front, but Saints were soon level as Wilson kicked a penalty earned at the scrum.
Jamie Elliott was forced to do some sterling defensive work at the other end, with the wing somehow chopping down the far more sizeable Logovi’i Mulipola.
But that saving tackle only provided a temporary reprieve as Tigers used a lineout drive to push Jordan Crane over the line.
Burns missed the conversion and Saints responded, with Brad Thorn’s blatant offside giving Wilson another three points.
The away side were displaying all of the fire and desire they had promised to deliver, with Mike Haywood’s huge hit on Julian Salvi earning a penalty.
Haywood walked away like a boxer who had just landed a knock-out blow as Saints went for the corner, with another penalty win allowing Wilson to put them ahead.
Tigers were looking tense and errors were costing them, with Christian Loamanu’s try ruled out for a Burns push on Ahsee Tuala in the build-up.
The home side needed a stirring second-half showing, and they started in the right manner, as Burns restored their lead with a penalty.
Ben Youngs thought he had extended the lead as he dived to try to touch down at the base of the post, but the TMO deemed that the scrum-half hadn’t scored.
Nevertheless, Tigers pushed on, putting Saints and in particular, Ma’afu under pressure at the scrum.
Ma’afu was replaced, but still the visitors struggled to cope with their rivals’ power, with Gareth Denman only involved in two scrums before being sin-binned.
The Tigers faithful were baying for blood and after Ma’afu came on to fill the gap left by Denman, the Australian was sin-binned for the very next scrum.
It meant scrums were now uncontested and Burns landed the penalty.
And Saints were soon in for more punishment as Niall Morris found a gap in the 13-man defence to score.
Burns hit the post with the conversion and Saints were determined not to go quietly, brilliantly winning a penalty as Ben Nutley did the business at the breakdown.
By the time Saints were back to full strength, Leicester had amassed a 10-point lead.
And that was to grow as Tommy Bell, on for the injured Burns, landed a penalty with 12 minutes to go.
Tom Stephenson threatened to make it interesting as he glided over the line with six minutes remaining, but Sam Olver’s missed conversion left Tigers eight points clear.
And Richard Cockerill’s men saw the game out to maintain their record of reaching the play-offs in every season since the current format was introduced in the 2005/06 season.
Leicester: Morris; Goneva, Tait, Loamanu (Roberts 70), Thompstone; Burns (Bell 66), B Youngs (Harrison 66); Mulipola (Ayerza 46), T Youngs (Thacker 73), Cole (Balmain 69); Thorn (De Chaves 58), Kitchener; Slater (Gibson 55), Salvi, Crane.
Saints: Tuala, Elliott (Packman 48), Waldouck, Stephenson, Collins; Wilson (Olver 68), Dickson (Fotuali’i 48); Corbisiero (A Waller 53), Haywood (Hartley 66), Ma’afu (Denman 50); Craig, Dickinson (Day 61); Dowson (c), Harrison (Nutley 56), Fisher.
Referee: Matthew Carley