Toulon made sure of a top-six finish and a place in the Top 14 play-offs courtesy of a 26-13 win at Bordeaux Begles on Saturday.
The three-time European champions have featured in four of the past five domestic finals and will have the chance to improve on that record after overcoming their hosts, who can no longer extend their season beyond next weekend.
Leigh Halfpenny kicked the first three of his 16 points to give Toulon the lead, which was stretched when Guilhem Guirado went over, Halfpenny adding the extras.
The Wales full-back slotted two more penalties either side of Baptiste Serin getting Bordeaux on the board as Toulon earned a 16-3 lead at the end of a half littered with yellow cards for Vadim Cobilas, Florian Fresia and Juan Smith.
Serin's penalty got Bordeaux back to within 10 in the 56th minute, but Halfpenny added another three before Liam Gill's try put the result beyond doubt, Jean-Marcellin Buttin's last-gasp score offering a measure of consolation for the home side.
With Montpellier not in action until Sunday, Clermont Auvergne took advantage to move into second place and stake their claim for a semi-final spot.
Ludovic Radosavljevic kicked 18 points in a 23-20 win at Lyon, who still harbour hopes of a top-six finish, as do Pau, who moved into the final qualifying spot with a 32-27 win over Brive, Watisoni Votu scoring two tries.
Castres are all but assured of their place after their 52-7 hammering of struggling Toulouse. The lead was just six points at half-time, but Castres scored 39 unanswered points in the second period, Benjamin Urdapilleta finishing with 27 in a one-sided affair.
Meanwhile, Bayonne won the battle of the bottom two sides with a 43-35 success over Grenoble.