"I'm extremely disappointed," said O'Neill about the 1-1 result which saw the home side fail to take maximum points despite having an overwhelming majority of chances.

"It's a game we clearly should have won."

Northern Ireland went in front after 14 minutes from a Dean Shiels strike, but numerous opportunities to add to the lead were missed before a deflected shot from Daniel Da Mota squirmed home via Ryan McGivern's shoulder with four minutes left.

O'Neill continued: "We had numerous chances in the first half to add to the one-goal advantage we had but we played poorly in the second half, although we did have chances to add to 1-0 as well, then we were caught out with a poor goal - a very unfortunate goal, to be fair - although our second half performance was well below the standard we expect."

Having set his team out for containment in Moscow, where NI lost their first qualifier, O'Neill selected a more attack-minded XI in Belfast and the team started with real purpose.

Jonny Evans thought he had made it 2-0 after 21 minutes from a neat corner routine but the goal was ruled out due to a push.

Unbelievably, the home side had a third effort struck off by the officials on the hour, when Kyle Lafferty in an offside position when he sidefooted Shane Ferguson's cross home.

Steve Davis gave Chris Brunt a chance to seal victory with seven minutes left but, after meeting the carefully-measured pass, he rolled his shot against the base of the post.

The sucker punch landed just moments later when Luxembourg surged up the pitch and Da Mota's shot careened off McGivern to leave Roy Carroll stranded.

"Whilst you couldn't see it coming, you were always thinking in the back of your mind that we're going to get caught here," O'Neill conceded.

"We didn't pass the ball as well, we let our energy levels drop and they came and pressed us a bit higher up the pitch and we didn't deal with that as well as could in possession.

"Subsequently we got a very disjointed performance which gave the ball away too easily and gave them a bit of hope."

Nigel Worthington lost his last four games in charge of the national side and since O'Neill's appointment there have been three defeats and two draws.

With just a single point from their opening two matches in Group F, Northern Ireland will now look ahead to a tricky game away to Portugal next month.

Meanwhile Luxembourg coach Luc Holtz was understandably in significantly higher spirits.

"You have to look at the clubs where the Northern Irish players play and where the Luxembourg players play ... it is a big difference," he said.

"In my opinion this is a big result for our team. This is a good result for us and when we play at home we are stronger than when we are away."