French coaches Fabien Galthie and Christophe Urios were given a four-week touchline ban on Thursday over a physical altercation between the pair when their sides met two weeks ago.
Castres boss Urios slapped Toulon's Galthie after the former's assistant Frederic Charrier and the latter got embroiled in an angry argument.
The French rugby league's disciplinary committee said the rival coaches were guilty of "words and behaviour that could affect the smooth running of the competitions".
It means they will both be banned from their sides' forthcoming European Champions Cup matches over the next two weekends.
Toulon play English side Bath and Castres are up against fellow Top 14 outfit Racing 92.
They will be free to sit on the bench again from January 1.
Charrier was handed the same punishment.
Urios, whose slap was more of a gentle flick, had admitted after the incident that the three had "behaved like children".
Both teams were fined 10,000 euros ($11,800) while Toulon were hit with an extra 5,000-euro penalty for allowing unauthorised people on the touchline.