Stephen Kenny claimed Ireland were ‘kicked in the teeth’ after blowing a lead away to Serbia.
And he fumed after striker Aaron Connolly was denied a second-half penalty in Belgrade that could have put Ireland 2-1 ahead.
"We're not losing the game at 2-1 up, that's for sure, and it was a very pivotal moment in the game," said the Ireland boss.
The Boys in Green were hoping to get off to a World Cup flyer after Alan Browne ended an 11-hour goal drought to snatch a deserved lead.
Instead, big Fulham striker Alexksander Mitrovic came off the bench to score two exquisite goals to leave the Boys in Green reeling after a second-half implosion.
Sub James Collins plundered a late goal but it wasn’t enough to force a point despite the positive performance.
And frustrated Kenny said: “You don’t get anything for that unfortunately, but the players were terrific.
“If you concede three goals in a game you have usually conceded six, seven or eight scoring chances.
“But Serbia scored with their first shot on target although they were ruthless with their finishing tonight.”
Kenny was raging after Brighton striker Connolly was denied a penalty early in the second-half as he felt it was a game-changing moment.
“That was really disappointing,” he said. “It looked like a cast iron penalty to make it 2-1. The player has gone through him!
“How could there not be VAR if there is for some matches and not for others? But look, there’s nothing we can do about that.
“I’m just disappointed about the second goal we conceded and, overall, I can’t believe we conceded three goals as it didn’t look like that type of match.
“We were comfortable defensively and Seamus Coleman marshalled the defensive brilliantly.
“But 3-1 is a kick in the teeth because you’re wondering how you’re 3-1 down but we worked hard and rallied and all of the subs made an impact.
“I think we have come out the wrong side of a narrow defeat.”
But Kenny refused to blame rookie goalkeeper Mark Travers - usually Ireland’s third choice - after Mitrovic caught him off his line with a sublime chip.
“Mark has been brilliant for us overall and he made a good save at the end of the first half. Overall the team’s attitude was brilliant.”
Ireland move onto the weekend when they host Luxembourg at Aviva Stadium on Saturday.
And while Kenny deployed a 3-5-3 formation for the first time, he refused to say if he would stick to that against the group minnows.
“We have to be flexible and we can’t tie ourselves to one system,” he said.
