Toulon set-up an all-French Amlin Challenge Cup semi-final against Stade Francais when they cruised past holders, and three-time winners, Harlequins 37-8 on Friday.
The home side, dominant throughout, out-scored injury-hit Quins three tries to one with Steffon Armitage, Benjamin Lapyeyre and Sebastien Tillous all crossing with Danny Care creeping over for a late consolation for the English side.
Jonny Wilkinson's metronomic left-boot added five penalties and a conversion - before he left the fray with a right-arm injury - while Australian centre Matt Giteau also slotted a penalty and a conversion for Toulon, the 2010 runners-up.
Quins had gone into the match looking under-powered with star Kiwi fly-half Nick Evans and captain Chris Robshaw both missing through injury.
France could have four teams in the semi-finals if Biarritz defeat Wasps on Saturday and Brive see off the Scarlets on Sunday.
Stade had booked their ticket to the last four with a 22-17 win over Exeter on Thursday.
Tries: Tillous-Borde, Lapeyre, Armitage
Cons: Wilkinson, Giteau
Pens: Wilkinson 5, Giteau
Yellow card: James Johnston (Harlequins, 50)
Toulon: 15 Benjamin Lapeyre, 14 Alexis Palisson, 13 Mathieu Bastareaud, 12 Matt Giteau, 11 David Smith, 10 Jonny Wilkinson, 9 Sébastien Tillous-Borde, 8 Joe van Niekerk (capt), 7 Steffon Armitage, 6 Pierrick Gunther, 5 Dean Schofield, 4 Christophe Samson, 3 Carl Hayman, 2 Sebastien Bruno, 1 Eifion Lewis-Roberts.
Replacements: 16 Jean-Charles Orioli, 17 Romain Frou, 18 Davit Kubriashvili, 19 Joe El Abd, 20 Gabi Lovobalavu, 21 Luke Rooney, 22 Fabien Cibray, 23 Jocelino Suta.
Harlequins: 15 Mike Brown, 14 Tom Williams, 13 Matt Hopper, 12 Jordan Turner-Hall, 11 Ugo Monye, 10 Rory Clegg, 9 Karl Dickson, 8 Nick Easter, 7 Luke Wallace, 6 Tom Guest, 5 George Robson (capt), 4 Tomas Vallejos, 3 James Johnston, 2 Rob Buchanan, 1 Mark Lambert.
Replacements: 16 Aston Croall, 17 Joe Marler, 18 Will Collier, 19 Peter Browne, 20 Maurie Fa'asavalu, 21 Danny Care, 22 Benjamin Urdapilleta, 23 George Lowe.
Referee: George Clancy (Ireland)