Castres had a player sent off inside the first four minutes for the second weekend in succession on Saturday but still carved out a 39-23 win over rock-bottom Agen in the French Top 14.
Last week, winger Yann David was red-carded in the fourth minute for a dangerous tackle on Josua Tuisova in the 15-14 win over Lyon.
On Saturday, it was Fijian winger Filipo Nakosi -- a half-brother of Tuisova -- who was sent off for a similar infringement after only three minutes.
Agen, who have now lost all 14 games this season, led 16-12 at the interval with winger Loris Tolot grabbing an early try and Paul Abadie kicking the extras as well as three penalties.
However, Castres finished the match with five tries in the bag from hooker Gaetan Barlot, winger Geoffrey Palis, who scored twice, prop Wilfrid Hounkpatin and Fijian centre Vilimoni Botitu.
Agen are now just one defeat from equalling the Top 14 record of 15 successive losses set by Perpignan in the 2018-2019 season.