Ireland have picked up one point from two games played and O'Neill knows that Wednesday's clash with Italy in Lille is one that carries greater significance.
Yet the manager knew that they would always require at least one victory to make it out of a difficult group and that remains the same.
“I always said from the outset that we would have to win a game in the competition to give ourselves a proper chance of going through to the next round of the tournament, and that is still the case,” said O’Neill.
“Obviously there is disappointment immediately after the game because we were upbeat going into the match following the performance against Sweden.
“The first goal (for Belgium) was a really vital goal, possibly because we could have had a penalty, and then they went and scored from the breakaway. But they were a very fine side, and I’m not taking anything away from that.
“But now we have a really great game against Italy to look forward to, to put our immediate disappointment to the side, and if we can win this game we give ourselves an incredible chance of qualification.”