Freddie Burns’ last-gasp penalty secured victory for Leicester over East Midlands rivals Northampton in dire conditions at Welford Road.
Tries from Matt Smith, Lachlan McCaffrey and Owen Williams gave Leicester a commanding 21-10 lead at the break
Tries from Teimana Harrison, George North and Jamie Gibson wrestled Saints back into it before Burns and Stephen Myler traded kicks to make it 27-27.
But Tigers, boosted by the return of Manu Tuilagi, stole it at the death.
A record crowd at Welford Park were treated to one of the best matches of the Aviva Premiership season, which saw Leicester open up a seven-point gap in the table over their local rivals with a 30-27 triumph.
Despite leading 21-0 at one stage, the Tigers were relieved to get the victory, while Northampton could feel hard done by only to come away with a losing bonus point.
The Tigers bounced back from their humbling away at league leaders Saracens last weekend by scoring three first-half tries in a blistering opening quarter via Matt Smith, Lachlan McCaffrey and Owen Williams, which give the hosts a commanding 21-0 lead at the break.
Saints though fought back through Teimana Harrison, whose try plus five points from the tee from JJ Hanrahan cut the deficit at the break to 11 points.
George North’s interception score after the restart sparked a fightback as Saints got back to 27-27.
But despite a phenomenal second half effort, much of the visitor’s hard work was undone when Burns slotted a penalty on the Saints 22 with the final touch of the game.
Leicester opened the try-scoring in under two minutes as good work from the backs ended with Smith throwing a dummy before diving over on the right. Williams then slotted the extra two points to give the hosts a seven-point lead.
A superbly architected lineout drive then saw the Tigers extend their lead after 20 minutes with McCaffrey dotting down. Williams then added the touchline conversion, 14-0.
Try number three followed soon after as Williams collects following an initial electric break from Ben Youngs to run in for the score and he added the conversion himself, making it 21-0 with 25 minutes gone.
Hanrahan then knocked over a penalty to get Saints on the board before the visitors got their first try on the edge of half-time. A superb finish from Harrison from a line-out drive added to Hanrahan’s successful conversion closed the gap to 11 points going into the break, 21-10.
Wales’ international wing North’s interception try from inside his own 22 soon after the restart got Saints right back into it with Hanrahan’s conversion closing the gap to just four points, 21-17
Replacement Freddie Burns edged Leicester ten clear from the tee with a pair of penalties.
Dan Cole though was sent to the sin-bin in the aftermath of the second penalty for the hosts, and Saints took advantage, with former Leicester flanker Gibson sliding over the line after breaking through a maul, with Stephen Myler kicking the extra two points.
And despite having Cole back on the pitch, the hosts were brought back to level terms for the first time since the second minute, thanks to Myler’s penalty, making it 27-27.
But after a grandstand effort, much of the visitor’s hard work was undone when Burns scored a penalty on the Saints 22 with the final touch of the game.
MAN OF THE MATCH
Leicester: Lachlan McCaffrey
Leicester: 15 Telusa Veainu, 14 Peter Betham, 13 Mathew Tait, 12 Matt Smith, 11 Adam Thompstone, 10 Owen Williams, 9 Ben Youngs, 8 Lachlan McCaffrey, 7 Brendon O’Connor, 6 Mike Fitzgerald, 5 Graham Kitchener, 4 Sebastian de Chaves, 3 Dan Cole, 2 Tom Youngs (c), 1 Marcos Ayerza
Replacements: 16 Harry Thacker, 17 Logovi’i Mulipola, 18 Fraser Balmain, 19 Laurence Pearce, 20 Tom Croft, 21 Sam Harrison, 22 Freddie Burns, 23 Vereniki Goneva
Northampton: 15 Ben Foden, 14 Jamie Elliott, 13 George North, 12 Luther Burrell, 11 Tom Collins, 10 JJ Hanrahan, 9 Lee Dickson (c), 8 Sam Dickinson, 7 Teimana Harrison, 6 Jamie Gibson, 5 Victor Matfield, 4 Courtney Lawes, 3 Paul Hill, 2 Mikey Haywood, 1 Alex Waller
Replacements: 16 Dylan Hartley, 17 Ethan Waller, 18 Gareth Denman, 19 Christian Day, 20 Tom Wood, 21 Tom Kessell, 22 Stephen Myler, 23 Harry Mallinder
Date: Saturday, January 9
Venue: Welford Road
Kick-off: 15:15 GMT
Referee: Wayne Barnes
Assistant Referees: Tim Wigglesworth, Peter Allan
TMO: Sean Davey