The long-running rivalry between factions of Paris Saint-Germain supporters reared its ugly head again on Tuesday as they clashed in Valencia after their team's Champions League match, resulting in eight arrests.
Carlo Ancelotti's side became the first French team to win at La Mestalla with a 2-1 triumph in the first leg of their last-16 tie, though the historic victory did little to calm the enmity between certain members of the 500-strong travelling PSG support.
Spanish police moved in after tensions between supporters from the opposing Boulogne and Auteuil stands at the Parc des Princes spilled over into violence in Valencia city centre.
The feud between the two groups has been on-going for a number of years, but reached a nadir with the death of a 37-year-old man in early 2010 following running battles in the streets of the French capital before and after a league match against PSG's arch-rivals, Marseille.
As a consequence, PSG initially stopped selling tickets for away games to their fans, while then club president Robin Leproux enforced stadium bans and the most virulent supporters' groups, who often have close official links to clubs, were dissolved.
The latest incidents are of particular cause for concern with PSG and bitter arch-rivals Marseille set to face each other twice in the space of four days later this month, clashing in Ligue 1 at the Parc des Princes on February 24 before their Coupe de France last-16 tie in the capital the following Wednesday.
Supporters of both clubs were banned from attending the respective away legs of France's 'clasico' last season, though PSG fans were able to attend the duo's Ligue 1 meeting last October while their OM counterparts could also travel to Paris for the Coupe de la Ligue clash later that same month.