Toulon leaped into third place in the Top 14 table after they manage to narrowly beat Castres 17-7 on Sunday.
The home side outscored their opponents by two tries to one, Josua Tuisova and Ma'a Nonu scored for the home side while Thomas Combezou was the only one to cross the whitewash for Castres.
The three-time European champions added seven points to their 10-0 half-time lead. Castres' discipline let them down to the point where two of their players saw yellow, one in either half.
Castres however failed to convert any of their possession or territory into points in the first half, Toulon's defence denied the visitors any opportunity of scoring.
A 22nd minute Jonathan Pelissie penalty handed Toulon an early advantage, Tuisova crashed over for his try with only three minutes to go in the half. Michalak's conversion took the score to 10-0 as the players headed into the locker rooms.
The All Black centre's try put a seal on the victory for the home side, Michalak added the extras and took the score well out of the reach of Castres.
Outside centre Combezou scored a late consolation try which replacement fly-half Julien Dumora converted that took the final score to 17-7.
Tries: Tuisova, Nonu
Cons: Michalak 2
Yellow Cards: Tichit, Wihongi
Toulon: 15 Quade Cooper, 14 Josua Tuisova, 13 Mathieu Bastareaud, 12 Ma'a Nonu, 11 James O'Connor, 10 Frédéric Michalak, 9 Jonathan Pélissié, 8 Duane Vermeulen, 7 Juan Martín Fernández Lobbe, 6 Juanne Hugo Smith, 5 Konstantin Mikautadze, 4 Mamuka Gorgodze, 3 Levan Chilachava, 2 Guilhem Guirado, 1 Xavier Chiocci
Replacements: 16 Jean Charles Orioli, 17 Alexandre Menini, 18 Romain Taofifénua, 19 Steffon Elvis Armitage, 20 Maxime Mermoz, 21 Theo Belan, 22 Eric Escande, 23 Mohamed Boughanmi
Castres: 15 Geoffrey Palis, 14 Rémy Grosso, 13 Thomas Combezou, 12 Rémi Lamerat, 11 David Smith, 10 Benjamín Urdapilleta, 9 Rory Kockott, 8 Alex Tulou, 7 Alexandre Bias, 6 Yannick Caballero, 5 Richie Gray, 4 Christophe Samson, 3 Karena Wihongi, 2 Marc-Antoine Rallier, 1 Mih%u0103i%u0163%u0103 Laz%u0103r
Replacements: 16 Julien Beziat, 17 Antoine Tichit, 18 Victor Moreaux, 19 John William Beattie, 20 Antoine Dupont, 21 Julien Dumora, 22 Rudolffe Nicholas Wulf, 23 Eric Sione