Record five-time winners Toulouse held off a second-half fightback from Harlequins to win a pulsating home Champions Cup semi-final 38-26 on Sunday and set a date with Leinster in the final at the Tottenham Hotspur Stadium on May 25.
Scrumhalf Antoine Dupont scored a brace of tries as the French side ran in six scores in all, with wings Matthis Lebel and Juan Cruz Mallia, hooker Peato Mauvaka and lock Thibaud Flament also getting over the try-line.
Harlequins trailed 31-12 at halftime but were a different team after the break and pulled to within five points of their hosts as they scored via flyhalf Marcus Smith, flanker Will Evans, wing Cadan Murley and fullback Tyrone Green.
Toulouse were playing a 16th semi-final and Harlequins their first, and that experience helped see out the contest as a yellow card for visiting hooker Jack Walker, gave them the impetus to pull clear in the final stages.
