Witsel had originally been banned until November 23, a punishment that would have kept him out for 10 matches in the league and one round of the Belgian Cup.
His fine has also been cut from 2,500 euros to 250 euros, the Belgian Football Association's appeals panel ruled on Friday.
In further good news for the player, the file will not now be sent to football governing bodies UEFA or FIFA. Witsel, 20, could have missed Liege's first four Champions League matches if UEFA had extended the ban's scope.
Witsel was sent off for stamping on Anderlecht's Polish defender Wasilewski in Sunday's 1-1 draw. Wasilewski suffered a double fracture of his right leg.
The incident has been the lead item on television news and pictures of Wasilewski's contorted lower leg have been splashed across Belgian newspapers.
Witsel has received emailed death threats, which the police have taken seriously, according to Belgian media.
Wasilewski's injury appears to be less serious than initially thought, however. The doctor of the Polish national team has said he could be back in training as early as March.
