French forward Sébastien Chabal was handed a three-week suspension on Friday for a punch that knocked out Agen's Marc Giroud, said club Lyon.
The 36-year-old former France international will miss his club's second division matches against Carcassonne, Narbonne and Albi before being available again on January 27.
During the December 14 match against Agen, Chabal had thrown a punch at Giroud, who was holding onto his shirt at a breakdown and preventing him from getting away.
Chabal pleaded guilty to an act of "brutality" and arriving at his hearing added: "In any case, the (television) pictures prove I'm guilty."
Giroud was knocked unconscious and had to be carried from the field on a stretcher before being taken to hospital for a medical check-up.
The bearded Chabal was shown a yellow card for the strike, which many observers felt was too lenient.
Chabal later apologised for his over-reaction saying it was "regrettable but a reflex action".
He told newspaper Le Progres: "There's not much else to say, except to apologise for my angry behaviour, which is not acceptable on a rugby pitch."
He had faced a suspension of between two weeks and one year at his disciplinary hearing on Friday.
In October, Clermont scrum-half Morgan Parra was given a four-week suspension, reduced to two on appeal, for raining punches down on Bordeaux-Begles' Spain flanker Gautier Gibouin.
Last January Racing-Metro's France hooker Dimitri Szarzewski was banned for 10 days, plus 20 days suspended, for having also punched No.8 Giroud.
"The penalty is appropriate for the action and, I repeat, regrettable and regretted," said Chabal in an interview with RMC radio station following the hearing.
"The punch wasn't premeditated and there's a scale. I was between two and five weeks, I've got three.
"If I'd have got more than five weeks, I'd have appealed because it wouldn't have been normal given the penalties given to other players for similar gestures.
"It's unfortunate but it will allow me to digest the foie gras and salmon I ate during the holidays and to prepare well for the end of the season with my club."