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 SUnday (AEST).

The three-time European champion has featured in four of the past five domestic finals and will have the chance to improve on that record after overcoming its host, which can no longer extend its 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 pulled 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 Monday (AEST), Clermont Auvergne took advantage to move into second place and stake its claim for a semi-final spot.

Ludovic Radosavljevic kicked 18 points in a 23-20 win at Lyon, which still harbours hopes of a top-six finish, as does Pau, which moved into the final qualifying spot with a 32-27 win over Brive, Watisoni Votu scoring two tries.

Castres is all but assured of its 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.