Newly-retired Ricky Ponting Monday blamed "one poor day in the entire series" against South Africa for costing Australia both victory and the number one ranking in Test cricket.
South Africa emphatically won the third and final Test at the WACA Ground by 309 runs to secure a 1-0 win in the series, and Ponting had no doubt the second day in Perth was the turning point.
Australia had the better of the first two Tests in Brisbane and Adelaide, but failed to clinch victory in either match.
Having dismissed South Africa on the opening day for 225, the home side was skittled for 163 in their first innings, and then had the game ripped away from them as the Proteas piled on 206 with the bat in the second day's final session.
"We know that one poor day in the entire series has cost us the series and the chance to get to number one in the world, which we all have worked so hard for and wanted so much," Ponting said.
"That is Test cricket though, you have to take your opportunities.
"We had some opportunities in Adelaide to get a win and go 1-0 up and maybe things might have been different."
Ponting praised the South Africans and said they were worthy of their lofty status.
"The fact they have beaten us at home and England at home in the last two series shows they are dominating world cricket," he said.
"They are a very good cricket team, we had to play very good cricket to win the series and we just about did that for 13 of the 14 days in this series.
"The cricket they played on day two, that was them imposing themselves on the series and they did it better than any team I have seen before."
Australia, minus their most decorated player, need to quickly regroup for the three-Test series against Sri Lanka, starting on December 14 in Ponting's home state of Tasmania.
They are set to regain the services of experienced fast bowlers Peter Siddle and Ben Hilfenhaus, who were both ruled out in Perth with fatigue, but most of the attention will focus on the replacement for Ponting in the batting line-up.
"Rob Quiney is the obvious one, having come into the series," Ponting said.
"He didn't perform the way he would have liked, but he was obviously the first choice batsman going into Brisbane.
"(Phil) Hughes and (Usman) Khawaja are out there scoring runs almost every game they play now.
"I honestly can't see it coming from outside those three and whichever way they go you can guarantee they will have a good replacement for me."
Australia clearly needs to bolster a shaky top order that was exposed by the Proteas, but captain Michael Clarke, who said his team's first innings batting cost it the Test, said he had not yet contemplated a replacement for Ponting.
"Someone has to come in for Ricky and I am sure the selectors have been thinking about that, but I haven't been," he said.
"I will talk to them tonight or tomorrow and we'll work out what is best for the team."
Clarke said he would consider moving in the batting order if it was best for the team.
He was pleased with the performances of left-armers Mitchell Starc and Mitchell Johnson, declaring that both had shown their value to the team.