* Two sent off after final whistle * Valbuena slapped in the face (Adds quotes, details) PARIS, April 27 (Reuters) - Mathieu Valbuena scored the only goal as Olympique Marseille consolidated second place in Ligue 1 with a 1-0 win at Lorient on Saturday in a game that ended in a mass brawl. Valbuena fired in a loose ball from just outside the box in the 25th minute. There were angry scenes at the final whistle after Fabien Audard slapped Valbuena in the face. Lorient goalkeeper Audard and Andre Ayew of Marseille were sent off as tempers flared among both sets of players. ... More...