The Champions League Group Stage is underway. Ahead of matchday four Arsenal are in a healthy position at the top of Group H, which features Olympiacos, Standard Liege and Tuesday night's opponents AZ.

Each week on Arsenal.com we'll be keeping track of how each side gets on in their domestic league. 

AZ Alkmaar

Groningen 0-1 AZ
Saturday, October 31

AZ warmed up for Wednesday's encounter with Arsenal at Emirates Stadium by earning a late victory over Groningen on Saturday. Jeremain Lens scored his fourth goal of the season in the 85th minute to give Alkmaar just their second win in five Eredivisie games. Ronald Koeman's side are seventh in the table, 14 points behind leaders FC Twente.

Olympiacos FC

Atromitos 0-1 Olympiacos
Saturday, October 31

Olympiacos remain level on points with top-of-the-table Panathinaikos after a 1-0 victory away at Atromitos on Saturday. Oscar Gonzalez scored the only goal of the game with 10 minutes remaining. Olympiacos remain unbeaten in the Greek Super League so far this season with eight wins and one draw from nine games.

Standard Li├Ęge

Excelsior Mouscron 0-0 Standard Liege
Friday, October 30

Standard Liege registered their seventh Belgium Pro League win of the season in a goalless game away at Excelsior Mouscron. After 13 games Standard are third in the table with 22 points, eight behind leaders Club Brugge.

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 2 Nov 2009