Luke Howell volleyed home the Dons' match-winning goal in the 88th minute with his first strike for the club.
"We are excited to be playing in the play-offs and it doesn't matter who we are going to play," said Di Matteo.
"We were lucky to keep a clean sheet having made some errors but it is another one and now we have to focus on the next game.
"It was a wonderful move from the team for the goal and Luke deserved it.
"We have got injuries but the players performed very well and I have to emphasise that the players who have come into the club have done really well. They have given everything and their commitment has been fantastic."