PARIS, Jan 30 (Reuters) - Troubled Paris Saint-Germain reached the French Cup quarter-finals on Tuesday courtesy of an error by Valenciennes goalkeeper Nicolas Penneteau.
Uruguayan striker Cristian Rodriguez was the lucky scorer in the 55th minute. The result boosts the Paris club, who have not won in their last 11 league games and were defeated at home by Valenciennes in a Ligue 1 match on Jan. 13.
Earlier in the day, Sochaux cruised into the last eight with a 2-0 win at Ligue 1 rivals Monaco.
Romain Pitau scored the opening goal in the 28th minute with a 20-metre shot into the far corner.
Sochaux, whose only Cup triumph was in 1937, sealed victory in the 64th minute with a header by Anthony Le Tallec, who had just come off the bench.
The surprise of the day came when Ligue 2 side Montpellier were ousted by third division Vannes after extra time. Jerome Lebouc and Cedric Rjillo scored in the 100th and 102nd minutes.
Ligue 1 Sedan came back from behind to win 2-1 at Libourne Saint-Seurin, who were promoted to Ligue 2 at the end of last season and have a reputation as Cup giantkillers.
Among the four games scheduled on Wednesday, Olympique Marseille host Ligue 1 leaders Olympique Lyon, who have not won the competition since 1973.