Spanish players attacked a referee after they believed he cost them a chance for direct qualification to the Rugby World Cup.
Romanian referee Vlad Iordăchescu was confronted after Spain lost 18-10 to Belgium in Brussels, meaning Romania qualifies for the Cup in Japan next year.
In the driving seat with a game in hand over Romania, Spain needed to defeat Belgium in the final round of European qualification matches to confirm their place.
However, Belgium raced into a 15-0 lead and, despite a late fightback, Los Leones could not finish the job off, meaning they will now face the play-off route.
The Spanish players, aggrieved at the end of the game, jostled the Romanian official in what were ugly scenes.
Romania finished second in the standings, a point above Spain. Georgia automatically qualified for the Rugby World Cup at the 2015 tournament.
Spain, who last made the World Cup in 1999, will play Portugal for the right to play Samoa home and away.
The winner on aggregate will join Romania in Pool A as the playoff winner, and the loser will go to a four-team repechage in November with Canada and two other teams.