Toulon overcame a red card shown to Mathieu Bastareaud to edge Castres 28-27 for their first Top 14 win of the season.
The three-time European champions sat bottom of the pile following defeats to Pau and Racing 92 in their opening two matches, with Castres boasting a pair of wins coming into this fixture.
And it looked like being another disappointing outing for the hosts when, at 27-20 down, Toulon captain Bastareaud was dismissed.
The France centre could have few complaints after his reckless forearm made contact with the head of a prone Castres player.
But Louis Carbonel reduced the deficit with a penalty five minutes from time before Filipo Nikosi touched down to salvage the win for a Toulon side who have looked a long way from their former glory in the early part of the season.
The result lifts Toulon to 11th, while Castres sit fifth after three matches.
In the day’s early kick-off, Pau won 24-21 to leave struggling Grenoble without a victory so far this season.
KEO.co.za News wire is powered by opta