Northampton Saints hooker Dylan Hartley has been handed a two-week ban for striking Ulster hooker Rory Best in the Round 3 Heineken Cup clash.
The England hooker will be free to play again on December 24.
"Hartley was alleged to have struck Ulster Rugby hooker, Rory Best (No 2), during the second half of the match at Franklin's Gardens in contravention of Law 10.4(a). The complaint was made by Citing Commissioner, Jean-Claude Legendre (France)," said an ERC statement.
"The independent Judicial Officer, Roger Morris (Wales), heard evidence and submissions by video conference from Hartley who pleaded guilty to the offence, and from his legal representative Richard Smith QC. Submissions were also heard from ERC Disciplinary Officer, Roger O'Connor.
"The Judicial Officer upheld the citing and employing the IRB recommended sanctions for Law 10.4(a), determined that the offence was at the low-end entry point of two weeks.
"When considering relevant aggravating factors the Judicial Officer added one week for the player's disciplinary record and then subsequently reduced the suspension by one week for the player's conduct during the hearing and guilty plea."