كتب : وكالات
The home side won 2-1 in Amsterdam, thanks to first-half goals from Demy De Zeeuw and Luis Suarez.
Slovenia midfielder Valter Birsa scored a consolation freekick for the French side after the break.
Ajax played for more than a half hour with ten men, following the sending off of Holland defender Andre Ooijer on 56 minutes.
However, Auxerre finished the game with two men down as Dennis Oliech and Jean-Pascal Mignot were both send off near the end.
In the same Group G, leaders Real Madrid maintained their 100% record with a 2-0 win over AC Milan in Spain.
Cristiano Ronaldo and Mesut Ozil were the heroes for Jose Mourinho's side, who have nine points at the top.
Milan and Ajax are tied on four points, but the Italians have a better goal difference. Auxerre are bottom with zero points.