Head coach Joe Schmidt admitted that even a draw would not have been enough for Ireland after losing to New Zealand.
Schmidt's third game in charge saw Ireland shock everybody watching by racing into a 19-0 lead against the number one team in the world early in the first half.
Jonathan Sexton's late missed penalty however left the door open for New Zealand and they levelled the scores through Ryan Crotty's overtime try, with Aaron Cruden landing the winning conversion on the second attempt to condemn Ireland to a heartbreaking defeat.
"You never feel the taste of victory in your mouth until the final whistle goes and we had to play to the final whistle and they got over in injury time," said Schmidt.
"We have to accept that. It's a game of three that we wanted and it's a game that I felt we were up for.
"Thanks to support we had, it was unbelievable. I hope they are not too disappointed, I certainly know that we are.
"We were in possession with 20 seconds to go and were penalised for off our feet and we had to defend that last phase.
"You've got to be prepared to defend to the end and we didn't quite keep them out."
Schmidt conceded that even if Cruden's first kick had stood - after falling wide to the right of the posts - drawing and failing to beat the All Blacks for the first time in Ireland's history would have been just as great a disappointment as the defeat.
"A draw was a loss to us to be fair," admitted Schmidt.
"We invested our time and energy in trying to win that game and I felt we went out with the right endeavour.
"We got some reward for our endeavour but we didn't get the reward in the end but we can't do much about that now.
"I felt we took a big step forward today. The measurement of progress will be if we can reproduce it and that'll be our challenge against Scotland in our Six Nations opener."