After last month's encouraging draw in Portugal, the team's Belfast blues returned with a 1-1 draw against lowly Azerbaijan. O'Neill was almost faced with a humbling defeat as Rauf Aliyev struck a sensational opener in the fifth minute before the hosts wasted a handful of wonderful chances.
After late substitute David Healy registered his first goal in four years, salvaging a point five minutes into added time, O'Neill said: "I'm hugely disappointed not to win the game because we did everything in our power to do that."
He added: "It's not good enough. We've drawn two games at home that we should have won. These are games we would expect to win but haven't done that.
"But I can't fault the players for the effort and they kept going right to the end. We probably played a little bit desperately at times and even early on we chased the game a bit.
"The players never stopped believing and they got the very least they deserved."
Fans' favourite Healy had not scored since October 2008 but finally ended the long wait for his 36th international goal when he drove a 95th-minute free-kick into the bottom corner. That raised the spirits of the crowd, who had otherwise endured disappointment after disappointment on the night.
O'Neill said: "It's not just about tonight and his impact on the pitch, he's just a good player to have around the squad.
"To have Healy around when the younger players come in is fantastic. He knows, realistically, that his impact for us now will be from the bench but it's great to have the option to throw him on.
"I'm delighted for him to get a goal because he's been a fantastic servant and however long he continues I know he has the personality to continue."
Source: PA
Source: PA