London Irish poured ice-cold water on Sale Sharks' play-off bid as they won 17-7 at Edgeley Park on Saturday.
The Sharks were 12-0 down at the break after a first-half horror show in which they were outwitted, outfought and above all outpaced by the impressive Exiles.
Tries from wing Topsy Ojo and centre Seilala Mapusua were the least the visitors deserved against a Sale outfit woefully bereft of ideas and inspiration.
Mapusua claimed his second in the closing stages to cap an exhilarating display of counter-attacking rugby from the visitors and although replacement Chris Bell replied late on for Sale, the hosts had long since surrendered the points.
Defeat for Philippe Saint-Andre's men - who were crowned Premiership champions two years ago - allowed Leicester to leapfrog them into fourth spot and claim a coveted play-off berth.
Sale began the day in fourth place and knew victory would assure them of staying there and possibly finish as high as second, depending on other results.
But they were a pale shadow of the side which marched to victory against Harlequins last weekend and the majority of a bumper 10,252 crowd were left bitterly disappointed at the final whistle.
Sale actually began the brighter but with Eoghan Hickey and Paul Hodgson dovetailing effectively at half-back, and Shane Geraghty providing additional guile and craft from inside centre, Irish cut their opponents to pieces at times during the first half.
That said, some obstinate defending was required to keep Sale at bay, particularly in the early exchanges and during the majority of the second half.
In the thirteenth minute, Sale full-back Ben Foden embarked on a typically marauding run from deep and his neat short offload found Richard Wigglesworth in support.
Wigglesworth - who came off second-best in his personal duel with opposite number and England rival Hodgson - kept the move flowing with a swift pass to Luke McAlister.
The Kiwi found the onrushing Brent Cockbain in support but some determined defence put paid to the forward's progress.
Two minutes later, Charlie Hodgson - who also failed to exert any meaningful influence on proceedings - then missed a drop-goal attempt from around 25 metres.
That Irish's opening try in the nineteenth minute emanated from a Sale mistake came as no surprise.
Wigglesworth's careless offload was intercepted and punished in devastating fashion by Ojo, who ran from ten metres inside his own half to outstrip the Sale defence and touch down.
It was a delightful score, converted superbly by Hickey, and laid the platform for Irish's victory.
Four minutes later, the Exiles had their second try when Sailosi Tagicakibau left a clutch of Sale players trailing in his wake down the left flank before a simple offload inside to Mapusa allowed the centre to saunter clear.
This time, Hickey could not convert and he and Hodgson also missed penalties before the break to ensure an interval scoreline of 12-0 in Irish's favour.
The pendulum swung towards Sale after the break but they simply could not pass a resolute Irish rearguard, despite the introduction of Sebastien Bruno and England pair Andrew Sheridan and Mark Cueto.
Even when Irish replacement Richard Thorpe was sin-binned midway through the second half - before being followed shortly after by captain Bob Casey - the visitors held firm.
Mapusua raced down the left flank for his second in the closing stages and although Bell responded for Sale with a try converted by McAlister, it was not nearly enough.
Tries: Ojo, Mapusua
Sale Sharks: 15 Ben Foden, 14 Selorm Kuadey, 13 Chris Bell, 12 Luke McAlister, 11 Andy Vilk, 10 Charlie Hodgson, 9 Richard Wigglesworth, 8 Sebastien Chabal, 7 Juan Martin Fernandez Lobbe, 6 Jason White (c), 5 Brent Cockbain, 4 Chris Jones, 3 Stuart Turner, 2 Neil Briggs, 1 Lionel Faure.
Replacements: 16 Sebastien Bruno, 17 Andrew Sheridan, 18 Eifion Roberts, 19 Dean Schofield, 20 Michael Hills, 21 Will Cliff, 22 Mark Cueto.
London Irish: 15 Peter Hewat, 14 Topsy Ojo, 13 Seilala Mapusua, 12 Shane Geraghty, 11 Sailosi Tagicakibau, 10 Eoghan Hickey, 9 Paul Hodgson, 8 Phil Murphy, 7 Steffon Armitage, 6 Declan Danaher, 5 Bob Casey (c), 4 James Hudson, 3 Faan Rautenbach, 2 David Paice, 1 Tonga Lea'aetoa.
Replacements: 16 Clarke Dermody, 17 Stuart Mackie, 18 Dan Murphy, 19 Gary Johnson, 20 Richard Thorpe, 21 Warren Fury, 22 Tomas De Vedia.
Referee: Chris White
Touch judges: Paul Emerson, Martin Buck
Assessor: Colin High
Television match official: Andrew Turner