The Italian giants were put at a disadvantage midway through the first half when Riccardo Montolivo was shown a red card for his offence against Ajax’s Christian Poulsen.
Down to ten men, the Rossoneri faced an uphill task but managed to hold on till the final whistle to claim a much needed point which put them through to the next round.
The San Siro bore witness to a determined fight as Massimiliano Allegri’s men held the Dutch champions at bay.
"We had to go through a lot, especially after the sending-off. We had to defend and we showed great character," Balotelli told reporters.
"It was difficult to score and the only way to get the result was to defend well. It depends from game to game but on Wednesday we were forced to defend with 10 men.
"We are a good group and we are showing it in every game. It was a very good duel against Ajax."
Balotelli then stressed that Milan now need to address their dismal Serie A form, with the Rossoneri currently ninth in the standings after a dreadful start to the season.
"We have done well in Europe but now we must do well in the domestic league," the former Manchester City forward declared.