Toulon claimed a 24-9 victory to condemn Pool 5 rivals Leinster to a third successive defeat in the European Rugby Champions Cup.
It was a solid start to the contest for the visitors as Jonathan Sexton punished some ill-discipline from Toulon with two penalties inside the opening five minutes.
The home side responded well to the early setback to find the first try when Samu Manoa benefited from a driving maul to cross over, before Eric Escande added the conversion.
Escande and Sexton traded penalties midway through the half, before Leinster's Cian Healy was sent to the sin-bin for a mistake in the ruck.
Despite surviving with 14 men on the pitch before the break, Leinster were dealt another blow when Devin Toner picked up a yellow card just moments after Sexton had missed the chance to hand his side the lead by sending a penalty just wide of the post.
Toulon capitalised on the advantage at the second attempt as Escande added two penalties to make it 16-9 while Toner served his time in the sin-bin.
Leinster battled impressively, but a comeback looked unlikely as the home side retained possession well without ever appearing to be at their best.
A tiring visiting scrum committed an error to give Escande the chance to take his tally to 14 points.
Tom Denton became the third Leinster player to visit the sin-bin late on as Toulon wrapped up the win in the final minute when Steffon Armitage came off the lineout to deliver a try as the hosts recovered from the loss to Wasps to claim their first victory of the campaign.