Middlesbrough midfielder Gary O'Neil admits he is in disbelief that his side failed to take all three points against Sunderland on Saturday.
Stewart Downing and Afonso Alves both forced good saves from Black Cats goalkeeper Craig Gordon before the break, but it was Downing's 75th minute penalty miss which proved most costly.
Michael Chopra eventually handed Sunderland the win with a late brace at the Stadium of Light, leaving Boro to pay for their missed chances.
"It's a hard one to analyse, because there is not too much wrong," said O'Neil.
"Two-nil massively flatters them. They will be delighted with the three points they have got, because I would say we deserved the full three points.
"I'm not too sure what to say about it. I felt we played well, probably should have taken one or two of our chances - and then it would have been a different game.
"But the penalty miss meant they got a bit of a lift and just one little lapse of concentration, and we were behind and chasing the game.
"It came as a bolt out of the blue. We didn't really know what had hit us."
The defeat means Boro are yet to take a point away from home so far this season and O'Neil admits it is a concern.
"It's something we desperately need to address," added the 25-year-old. "Right at this second, I am not too sure what the problem is.
"Maybe we just go under a little bit too easy when the going gets tough, like it did when Stewart missed the penalty.
"They seemed to get on top; they got a lift; the fans got a lift - and it became a big five minutes for them.
"That's the spell where we need to make sure we weather that and get through that still at 0-0.
"Maybe there was a little bit of naivety in still trying to go out and score."