Brumbies flyhalf Noah Lolesio has completed his stint with Toulon, ending with victory.
Lolesio contributed 15 points in the 30-27 win over former teammate Folau Fainga'a and Clermont.
The playmaker kept Toulon in the contest after a slow start, with Fainga'a crossing the line in the 31st minute to give Clermont the early advantage.
Lolesio slotted penalties on either side of half-time to put Toulon in front, with backrower Jules Coulon's second try of the game extending their lead.
Clermont mounted a comeback and hit the front with ten minutes to go before Fijian international Jiuta Wainiqolo scored in the 78th minute for the win.
Lolesio will return to the Brumbies as his joker stint concludes, having started the past fortnight in place of Dan Biggar.
It also served as Alun Wyn Jones' final game for Toulon, with the 38-year-old departing the field to a standing ovation.
Meanwhile, La Rochelle prepared for Siya Kolisi's Racing 92 debut next weekend with a 25-21 win over Bordeaux-Begles on Sunday in the French Top 14.
Ronan O'Gara's side moved up to eighth in the table with just their third win of the season, a week before facing Racing in Kolisi's expected first game for the Parisians. Bordeaux-Begles dropped to 10th with their fourth loss of the campaign.
France winger Damian Penaud made his first Bordeaux-Begles start after his move from Clermont as ex-New Zealand scrum-half Tawera Kerr-Barlow captained La Rochelle, two-time Champions Cup holders under former Ireland fly-half O'Gara.
Penaud's outfit led 9-8 at the break thanks to three penalties from his Test and club team-mate Matthieu Jalibert, while hooker Pierre Bourgarit crossed from a rolling maul for the hosts. Penaud set up centre Nicolas Depoortere before crossing for a superb effort of his own after a Jalibert cross-kick and Bordeaux-Begles led 21-8 with 25 minutes to play.
But La Rochelle claimed victory thanks to Samoa centre UJ Seuteni's try and Bourgarit's second, as 19-year-old replacement fly-half Hugo Reus slotted two conversions.
Reus then completed the comeback against their Atlantic coast rivals with a long-range penalty to make it 25-21 with nine minutes to go, mirroring his impressive goal-kicking efforts in last weekend's win over Bayonne.
"I think we've started our season now, it will do us a lot of good, it was an important victory," O'Gara told broadcaster Canal+.
"We're in a tough period but I'm very proud of the players, and the crowd."