Ireland coach Eddie O'Sullivan felt his side paid the price for poor finishing during the 30-14 defeat by Australia at Lansdowne Road on Saturday.
The Wallabies scored three second-half tries to Ireland's single effort and O'Sullivan admitted that "it was a harsh lesson".
"We had chances in the game but you must finish them or you the pay the price at this level," he said.
"Their intercept try was the one that killed us off completely."
O'Sullivan revealed Malcolm O'Kelly had been knocked out cold in the first half following a double tackle by Lote Tuqiri and Hugh McMeniman but added the veteran had recovered.
"Malcolm has come round and he's fine. He's good," said O'Sullivan who believed Ireland were well in the game at the break.
"We were well in control of the game at half-time, and I was happy with things, although we should probably have been a little further ahead.
"The start of the second half killed us off as we coughed up 10 points in five minutes.
"We were still very much in the game though until a series of events killed us off and knocked the stuffing out of the team.
"But the positives are that we defended a lot better that we did against New Zealand, but our line-out was a bit shaky in the second half.
"But overall I don't think we were too far off the pace. We had our chances to score, but if we don't finish things off at this level you are punished for it."