A late converted score from Gonzalo Camacho saw Harlequins win 19-18 on Friday, snatching the Amlin Challenge Cup from Stade Franšais' grasp.
The wing's try with two minutes remaining on the clock still needed to be converted from five metres inside the touchline, which former All Blacks playmaker Nick Evans coolly slotted to secure the London side their third Challenge Cup triumph and a place in next season's Heineken Cup.
Stade Franšais owed their points to four Lionel Beauxis penalties while Mathieu Bastareaud and Martin Rodriguez each kicked a drop-goal.
The giants from Paris will now be cheering for Northampton in the Heineken Cup Final against Leinster, which takes place in the stadium next to this. However, if the Irish giants were to beat Saints, then Connacht would join Europe's elite.
What is guaranteed is that England will have seven teams in the 2011/12 competition thanks to a dramatic win that was inspired by Danny Care.
The international scrum-half was a key protagonist for Quins and had the intelligence to send through a teasing kick that Camacho latched on to. Evans, despite the angle, showed his class to convert to leave Stade Franšais in a race against time that they ultimately lost.
Pen: Evans 4
For Stade Franšais:
Pen: Beauxis 4
Drop: Bastareaud, Rodriguez
Stade Franšais: 15 Martin Rodriguez, 14 Julien Arias, 13 Mathieu Bastareaud, 12 Guillaume Bousses, 11 Djibril Camara, 10 Lionel Beauxis, 9 Julien Dupuy, 8 Sergio Parisse, 7 Antoine Burban, 6 James Haskell, 5 Pascal Pape, 4 Tom Palmer, 3 David Attoub, 2 Remi Bonfils, 1 Rodrigo Roncero.
Replacements: 16 Damien Weber, 17 Rayno Gerber, 18 Arthur Joly, 19 Arnaud Marchois, 20 Pierre Rabadan, 21 Juan Leguizamon, 22 Noel Oelschig, 23 Ollie Phillips.
Harlequins: 15 Mike Brown, 14 Gonzalo Camacho, 13 George Lowe, 12 Jordan Turner-Hall, 11 Ugo Monye, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw (c), 6 Maurie Fa'asavalu, 5 George Robson, 4 Ollie Kohn, 3 James Johnston, 2 Joe Gray, 1 Joe Marler.
Replacements: 16 Matt Cairns, 17 Ceri Jones, 18 Mark Lambert, 19 Pete Browne, 20 Will Skinner, 21 Dave Moore. 22 Rory Clegg, 23 Ross Chisholm.
Referee: George Clancy