Gloucester powered to a comprehensive 30-17 win over top-of-the-table rivals Leicester at Welford Road on Saturday.
Willie Walker's personal tally of 20 points added to a penalty-try and Leon Lloyd's effort against his former club completed the Cherry and Whites' impressive performance.
It is only the second home Guinness Premiership defeat on the Tigers in the last 40 games, and it takes Gloucester well clear at the top of the table.
Both sides had three wins from their opening three games with Gloucester on top having claimed two bonus points.
They were the division's pace-setters last season and clashed in the Grand Final, with Leicester winning 44-16.
They also fought out a thrilling 27-27 draw at Welford Road last season.
Leicester welcomed back Geordan Murphy and Martin Castrogiovanni from World Cup duty as they set about improving an impressive home record that showed only one defeat in the previous 39 Premiership games.
The match marked Leon Lloyd's first appearance at Welford Road since he joined Gloucester in the summer.
Lloyd spent 13 years at Leicester and returned on the wing in place of the injured James Simpson-Daniel.
Ryan Lamb was named the Guinness Premiership's player of the month for September, but head coach Dean Ryan decided to give Kiwi Willie Walker his first start of the season at fly-half.
His opposite number Andy Goode was off target with a third-minute penalty attempt - and then his pass a few seconds later was intercepted by Lloyd, who galloped through unchallenged from 20metres out to touch down between the posts.
Walker's conversion made it 7-0, before a spell of Leicester pressure led to Goode trimming the gap with a 14th-minute penalty.
Walker kicked a 17th minute penalty to restore the seven-point lead and Gloucester were 14 points clear after 23 minutes when referee Roy Maybank awarded a penalty try following a Leicester infringement at a scrum five metres from their own line.
Walker converted and he kicked the Cherry and Whites further clear on 31 minutes with a 45 metre penalty.
Leicester needed to trim the gap before the break and Goode missed two penalty attempts in the dying moments of the half to leave the visitors leading 20-3 at the break.
Leicester head coach Richard Cockerill replaced Goode at the break with Paul Burke.
Leicester were relieved after 48 minutes when video replays showed Luke Abraham and Brett Deacon had held up skipper Peter Buxton just short of the line.
But there was to be no reprieve two minutes later when Walker's penalty made it 23-3.
Tom Croft gave Leicester a glimmer of hope with 10 minutes left when he took Matt Cornwell's pass in his stride and powered through a couple of tackles to touch down.
Burke's conversion trimmed the gap to 13 points.
The joy among the home supporters was short-lived. Walker danced his way through a tired Leicester defence to touch down and his conversion took his personal points haul to 20 points.
Leicester wouldn't give up and Cornwell crossed with two minutes left. Burke converted.
Tries: Croft, Cornwell
Con: Burke 2
Tries: Lloyd, Penalty, Walker
Con: Walker 3
Pen: Walker 3
Leicester: 15 Geordan Murphy, 14 Johne Murphy, 13 Ollie Smith, 12 Matt Cornwell, 11 Tom Varndell, 10 Andy Goode, 9 Frank Murphy, 8 Jordan Crane, 7 Luke Abraham, 6 Brett Deacon, 5 Marco Wentzel, 4 Louis Deacon (c), 3 Julian White, 2 Benjamin Kayser, 1 Alex Moreno.
Replacements: 16 Mefin Davies, 17 Martin Castrogiovanni, 18 Richard Blaze, 19 Tom Croft, 20 Ben Youngs, 21 Paul Burke, 22 Ayoola Erinle.
Gloucester: 15 Olly Morgan, 14 Leon Lloyd, 13 Mike Tindall, 12 Anthony Allen, 11 James Bailey, 10 Willie Walker, 9 Mike Prendergast, 8 Luke Narraway, 7 Andy Hazell, 6 Alasdair Strokosch, 5 Alex Brown, 4 Peter Buxton (c), 3 Carlos Nieto, 2 Olivier Azam, 1 Patrice Collazo.
Replacements: 16 Andy Titterrell, 17 Christian Califano, 18 Nick Wood, 19 Will James, 20 Gareth Cooper, 21 Mark Foster, 22 Ryan Lamb.
Referee: Roy Maybank
Touch judges: Peter Huckle, Alan Hughes
Assessor: Brian Leigh
Television match official: Matt Peters