Lille's hopes of a morale-boosting victory before their Champions League clash against Valencia next week were shattered by a 2-0 loss at Rennes on Friday.
To make matters worse for the 2011 French champions, they also had coach Rudi Garcia red-carded in the last minute.
Julien Feret, after 64 minutes, and Alessandrini, 11 minutes later, grabbed the goals as Rennes moved out of the relegation zone and into 12th place in the Ligue 1 table.
It was their second win of the week following a 3-2 triumph over Nancy in the League Cup.
Lille, however, have only one league win in seven games this season and that was on the opening weekend when they won 2-1 at Saint-Etienne.
They are in 13th place in the standings.