Harlequins look set to bow out of the Heineken Cup after losing 9-8 to Connacht at the Sportsground in Galway on Friday.
With Toulouse losing in Gloucester, victory would have put Quins into the quarter-finals but three first-half Niall O'Connor penalties were enough for Connacht to secure their first ever Heineken Cup win.
Connacht won their first match since September and ended a dismal 14-game losing run to all but dump Harlequins out of Europe.
At wet and windy Galway, playing into a driving gale and heavy rain, Harlequins would have been content going in at half-time only four points in arrears.
The Londoners adopted keep-ball tactics in the first half, knowing that tactical kicking was not an option, and they managed to turn possession into points in the eighth minute thanks to a try from Sam Smith.
Smith grounded the ball in the right-hand corner following a neat wrap around move involving Nick Evans and Jordan Turner-Hall.
Connacht offered little in attack but O'Connor's boot gave them a narrow half-time advantage.
Having weathered the storm well in the first 40 minutes, Harlequins dominated the early stages of the second period and they should have been in front but Ugo Monye was unable to gather in Evans' chip kick ahead over the try-line.
Quins were then embarrassed at scrum-time, losing control at the base five metres from the home side's line when they had previously rejected kickable attempts at goal.
Connacht continued to tackle themselves to a standstill, Harlequins pounding away at a brickwall defence without any joy for the entirety of the third quarter.
A three-pointer from Evans just after the hour-mark provided the first points of a tense second half, but the Kiwi was unable to convert his next opportunity and Harlequins were left to reflect on an opportunity missed given Toulouse's shock defeat at the hands of Gloucester.
Pens: O'Connor 3
Connacht: 15 Gavin Duffy (capt), 14 Fetu'u Vainikolo, 13 Kyle Tonetti, 12 Dave McSharry, 11 Tiernan O'Halloran, 10 Niall O'Connor, 9 Paul O'Donohoe, 8 George Naoupu, 7 Ray Ofisa, 6 John Muldoon, 5 Mike McCarthy, 4 Michael Swift, 3 Ronan Loughney, 2 Adrian Flavin, 1 Brett Wilkinson.
Replacements: 16 Ethienne Reynecke, 17 Denis Buckley, 18 Dylan Rogers, 19 Mick Kearney, 20 Eoin McKeon, 21 Dave Moore, 22 Miah Nikora, 23 Henry Fa'afili.
Harlequins: 15 Mike Brown, 14 Ugo Monye, 13 Matt Hopper, 12 Jordan Turner-Hall, 11 Sam Smith, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw, 6 Maurie Fa'asavalu, 5 George Robson, 4 Tomas Vallejos, 3 James Johnston, 2 Chris Brooker, 1 Joe Marler.
Replacements: 16 Joe Gray, 17 Mark Lambert, 18 Tim Fairbrother, 19 Olly Kohn, 20 Luke Wallace, 21 Richard Bolt, 22 Rory Clegg, 23 Tom Casson.
Referee: Nigel Owens (Wales)