Isa ended the game with a hat-trick of tries but it was mixed performance from the Argentine back row as he made key errors to gift Saracens a couple of early tries.
The first was a dropped ball as Jaminet opted to fire a pass wide rather than clear his lines deep inside Toulon territory, which the number eight fumbled before his compatriot Gonzalez picked to score the opening try.
Jaminet quickly made amends as his break set up Wainiqolo to open Toulon’s account but Saracens, driven forward by influential England hooker Theo Dan, moved in front once again through Tompkins.
Centre partner Hartley then added a fine finish with a first-phase strike play in midfield to score Saracens’ third before Gonzalez was the beneficiary of another error by Isa, who lost control of the ball after making a clever turnover, to score potentially the easiest double of his career.
Another charging run by Dan, who proved a constant threat in the first half, set up Van Zyl to cross for the fifth in a whirlwind opening by the visitors.
Isa reduced the deficit with a powerful surge from close range before Jaminet crossed in midfield to hand Toulon a reprieve and a route back into the game.
The hosts emerged from the sheds revitalised and Brian Alainu’uese drove over the line to maintain their momentum before Isa sealed his hat-trick with another fierce carry after picking up the ball from the base of the ruck.
Toulon’s physical approach began to take its toll on their English visitors, creating space in the wide channels, and Gabin Villiere made a break close to the touchline and fed Fainga’anuku on the inside for a run-in.
Sarries needed a lifeline and it came in bizarre circumstances from a penalty, which was nudged to touch and recycled for Hadfield’s try, after Toulon were penalised for momentarily having 16 players on the pitch.
It would prove to be a consolation, though, as Villiere added another clever assist moments later for Serin to dive over in the corner, before Tuicuvu added the hosts’ 10th try.
