Arsenal had David Luiz sent off before the half-hour mark but Hector Bellerin ensured they left Chelsea with a point.
Goal-shy winger Alireza Jahanbakhsh scored for a second game running as Brighton battled to a point at home to Chelsea on Wednesday.
Antonio Rudiger alleges he was targeted with racist abuse during Sunday's 2-0 win at Tottenham and it has been raised with officials.
After Antonio Rudiger reported racist abuse at Tottenham on Sunday, Cesar Azpilicueta called for "the eradication of the problem".
Freddie Ljungberg has been named interim boss of Arsenal and former team-mate Ashley Cole wants him to land the job on a permanent basis.
Chelsea completed the job against Lille as Tammy Abraham and Cesar Azpilicueta sent the Blues through to the Champions League's last 16.
Tottenham head coach Jose Mourinho was sent well wishes by Chelsea captain Cesar Azpilicueta.
Chelsea conceded three first-half goals in a Champions League game for the first time but battled back against nine-man Ajax to draw 4-4.
Chelsea head coach Frank Lampard has challenged his players to show more consistency in matches after their nervy 2-1 win at Watford.
Callum Hudson-Odoi's tough outing against Ajax should not worry Chelsea, says captain Cesar Azpilicueta.