Irish coach Warren Gatland was in no mood to pull his punches as his side were unable to find any way through against Australia.
"I was very disappointed with the performance - we were well beaten by a good Australian side," said Gatland.
"We really didn't fire a shot. We were nowhere near as accurate as we needed to be and we really let ourselves down out there. The players seemed pretty flat, but there are no excuses for our performance.
"We simply weren't able to pick it up. They applied pressure and we didn't respond. We didn't play well enough to give the crowd something to cheer about."
Gatland, meanwhile, believes Australia have the ability "to go all the way" in the World Cup.
"They are very strong up front and will become a lot stronger unit," he said. "They are well-prepared and well organised and they will be tough to beat later on."