كتب : Ahmad Saied
The Gunners are now six points clear at the top of Group H with one game left in the group stage.
Olympiakos are second with seven points after they settled to a goalless draw with AZ Alkmaar on the same day.
Samir Nasri broke the deadlock in the 35th minute when he controlled a cross from Thomas Vermaelen before steering the ball past keeper Sinan Bolat.
Just before the goal, Arsenal's William Gallas and Andre Arshavin were down in blood after a clash of heads as both players attempted to connect with a cross from Cesc Fabregas.
Denilson ensured the victory just before the break with a long-range shot after being set-up by Kieran Gibbs.
Mohamed Sarr could have pulled one back for Standard in the closing stages of the match when he unleashed a powerful shot that struck the post.