The game on Monday ended in a 1-1 draw, after Dunne had opened the scoring for Villa.
“Over the course of the game I’m disappointed with the result, but not with the performance,” O’Neill told ESPN. “The team were absolutely fantastic.
“We haven’t played better. We pressed, we got the goal we deserved, but they’re a very, very good team and you’re not going to outplay them for the whole game.
“They got the goal and the game was end to end.
“But I’m delighted with the performance of the team.
“I would have loved to have got three points but I’m pleased with the side and pleased with the crowd.”