O’Neill believes the win, which stretches their unbeaten streak at home to seven games, shows the maturity of his young side and how good they can be.
“I think they understand now the levels they can get to, there is still more to go with this group of players,” he added.
“Tonight, we showed what we can be like at home, we have shown this before if you look back to the Bulgaria game, but we played a better team tonight and we showed it against a very good team.”
Reluctant to single out players given so many performed well, O’Neill did praise captain on the night Conor Bradley for being the catalyst for NI’s good play particularly down the right-hand side.
“From the word go he was magnificent, his energy, him and Ethan [Galbraith] on were terrific on that side with their link up and quality,” he explained.
“We have so many good young players who love playing together. It is difficult to pick one player, Conor does stand out because he does so many good things, it was good for him to captain the team on a night like this.”
The only dampener on a positive night for NI was that Bradley picked up a yellow card that will rule him out of the crucial meeting with Germany in Belfast on Monday.
O’Neill was frustrated by the decision and believes the yellow card was “extremely” harsh.
“I have watched it back and he tries to pull out. The referee, at times, it was good he didn’t want to hand out yellow cards but if he was going to give a yellow for that he should have dished out more. Especially for the opposition.”