(1st leg result Wasps 35 -22 Stade)
Scottish wing Kenny Logan steered London wasps into the last four of the PARKER PEN CHALLENGE CUP with an 80m interception try, and a 52m penalty goal.
Logan's run put Wasps back ahead after Diego Dominguez's third penalty goal had given Stade a brief 9-8 lead midway through the first half.
After Logan had raced clear for his try which Alex king converted, Wasps never looked back and were convincing winners over the two legs.
That Logan try was Wasps' second in ten minutes as they made Stade's task in winning a ticket to the semi-finals seem more and more impossible.
John Rudd raced 60m to pave the way for Fraser Waters to run in the opening try, and with Logan and King exchanging penalty goals before the break, the visitors were 21-9 ahead at half-time and 25 points clear in the tie.
Dominguez kicked a fourth penalty goal four minutes into the second half but a 52m special from Logan kept Wasps ticking over and King completed the scoring after 70 minutes with his third penalty goal.
And as if to rub salt into Stade's wounds, Dominguez was carried off on a stretcher at the end after hitting his head in a tackle.
Stade Francais: I Corletto; T Lombard, S Glas, B Liebenberg, C Dominici; D Dominguez, F Galthie (capt); S Marconnet, B August, P de Villiers, D Auradou, M James, C Moni, R Martin, P Tabacco
Replacements: B Cabello, P Lemoine, P Rabadan, R Jechoux, F Comba, A Gomes, J Fillol
London Wasps: M van Gisbergen; J Rudd, F Waters, S Abbott, K Logan; A King, R Howley; C Dowd, T Leota, W Green, S Shaw, R Birkett, J Worsley, P Volley, L Dallaglio (capt)
Replacements: M Wood, P Greening, M Denney, A Erinle, P Scrivener, J Beardshaw, A Kershaw
Stade Francais 12 London Wasps 27
HT: 9-21 Attendance: 6,491
Stade Francais: Pens - D Dominguez 4
London Wasps: Tries - F Waters, K Logan; Con - A King; Pens - A King 4, K Logan
London Wasps qualify for the semi-finals
Stade Francais: 21/12 Beat Grenoble 25-13(h)
London Wasps: 21/12 Lost Bath Rugby 17-20(h-Powergen Cup Rd 6); 27/12 v Leicester Tigers (h-Zurich Prem).