Glasgow flanker Ryan Wilson has escaped suspension after being accused of grabbing the testicles of Northampton scrum-half Lee Dickson.
Scotland back-rower Wilson had a citing complaint against him dismissed by European officials in a disciplinary hearing in London.
The 26-year-old is now free to return to action for both club and country, if required, given he could yet feature in Scotland's Six Nations campaign despite missing initial selection.
Wilson pleaded not guilty to the offence, with independent judicial officer Simon Thomas effectively throwing out the case.
"As the judicial officer was not satisfied to the required standard that the act of foul play as alleged had been committed, the citing complaint was dismissed and Wilson is therefore free to play," read a statement from European Professional Club Rugby (EPCR).
Wilson could have faced a minimum 12-week ban had he been found guilty of the offence, but is now free to return to action without delay.
Newport Gwent Dragons star T Rhys Thomas also saw an allegation of biting dismissed in a busy disciplinary day.
Thomas had been alleged to have bitten Castres flanker Thomas Caballero in the Dragons' 31-18 Challenge Cup victory on Friday night, but was cleared by independent judicial officer Rod McKenzie.
Finally, Glasgow and Scotland lock Tim Swinson was handed a one-week ban for punching Northampton hooker Mikey Haywood in Sunday's Champions Cup clash.
Swinson was sin-binned for the incident, and pleaded guilty to the offence in Wednesday's disciplinary hearing in London.
Independent judicial officer Simon Thomas deemed the offence worthy of a red card, and imposed a suspension of two weeks that was then halved due to the guilty plea, Swinson's remorse and clean disciplinary record.
Swinson is free to play from Monday, January 25, allowing the 28-year-old to take full part in Scotland's Six Nations campaign.