Despite the fact that both teams played largely reserve teams the Latics ran out comfortable winners with goals from Mauro Boselli (2), Ivan Ramis, and Jordi Gomez.
Manager Roberto Martinez hailed what he called a 'fantastic night'. He told the club's official website: “We’re really pleased because we made a lot of changes at the start of the night which meant it would take time during the game for those little partnerships to form.
“It was therefore always going to be an open game in those early stages and we got off to the worse possible start with the goal West Ham scored.
“But the reaction was outstanding – we coped with their pressure really well and our football was very sharp in opening up the opposition.
“You then have individual performances of a high quality, including Mauro Boselli who deserved his goals and took them very well.
“That was really important for him because he’s a goalscorer and I’ve said from the beginning of the season that he looks sharp, is very focused and a player of that stature is going to be very important to us this season.
“Callum McManaman showed he’s a player ready to step in, Ryo Miyaichi brought together all the concepts of his training so far at the club and David Jones paired well with James McArthur very in the midfield ahead of the defence.
“Players took responsibility all over the pitch which was very pleasing after the disappointment of last weekend. In front of goal we were a real threat, looked clinical and in many ways shook off the weekend’s disappointment.
“There were players who have been waiting for a chance to play this season that made a good impression at Nottingham Forest in the previous round and did so again tonight, which develops the competition in the squad further.
“Let’s not forget also that we took on a West Ham side high on confidence having not been beaten at home this season before our game and doing well in the league, which all made for a very pleasing night.”
Next up for the Latics is the tricky trip to Sunderland to face Martin O'Neill's revitalised side at the weekend.