A brace by Obafemi Martins secured the win for Newcastle.
“We will fight back. That is what it is all about,” O’Neill told Setanta Sports. “We have to.
“As you can see yourself, we are far from the finished article. We want to be battling and be up there and tonight was disappointing.
“On the first half performance, we probably should have been out of sight.
“We had great chances to win the game and couldn’t get our noses in front. We had a number of chances and I thought we played exceptionally well first half.
“Second half we were far from our very, very best. I thought we would conjure up the chances but it never really fell for us. But we shouldn’t have lost.
“Gabby [Agbonlahor] has a great chance and he mishits it in front of goal and normally he would put it in the net. But we had a number of chances – Martin Laursen hit the post early on.”