Dubai: India`s dismal performance in the international season gone by pushed them down the ladder in the ICC Test rankings with the team finishing fifth in the annual updated list issued on Thursday.
Australia have gone top in both the formats for the first time since December 2008. Australia last held the number-one Test ranking in August 2009, when they were displaced after losing 2-1 to England.
India, who were thrashed during trips to South Africa and New Zealand in their most recent Test assignments, have slipped from third to fifth in the table after dropping 10 ratings points.
In the ODIs list, Mahendra Singh Dhoni`s men held on to the second spot.
India`s 2010-2011 victories against Australia, New Zealand and West Indies (away), as well as a drawn series against South Africa, no longer count to the rankings.
Similarly, India`s 2011-2012 victory against the West Indies, and 2012-2013 victories against New Zealand and Australia are now weighted at 50 per cent.
There has been little change to the ODIs rankings, despite the top three sides -- Australia, India and Sri Lanka -- seeing their rating drop.
Australia have now edged ahead of South Africa, a team which had held the number-one position since August 2012.
In the latest table, Australia have gained eight ratings points to move up from 115 to 123, while South Africa has dropped from 127 to be level on 123, with Australia ahead of South Africa by a fraction of a point, the ICC said in a statement.
The results from 2010-11 have now been dropped from the rankings calculation, while the results from 2012-2013 are now reduced to a weighting of 50 per cent. In 2010-2011, Australia had lost to India (2-0) and England (3-1), while they suffered a 4-0 defeat in India in 2012-2013.
Australia captain Michael Clarke was delighted with the news that his side was now on top of both the Test and ODI tables.
Looking back at the past season, which has turned out to be the cornerstone of Australia`s rise to the number-one ranking in Tests, Clarke said: "We had a fantastic home summer against England and a great series win away against South Africa earlier this year, but the challenge now is to continue that form.
"We have a huge amount of respect for the South Africa side, and the length it held the number-one Test ranking is testament to the great side it is. South Africa will no doubt continue to be a formidable opponent in Test match cricket," said Clarke.
Australia were the first team to be ranked number-one in Test cricket when the ICC introduced the current rankings system in 2003.
Since the system was introduced, Australia has been ranked as the number-one Test side for 74 months, more than any other side. South Africa are a distant second, having spent 23 months on top.
South Africa had outstanding 2011-2012 and 2012-2013 seasons when it won six of the seven Test series it played. It defeated Sri Lanka (2-1), New Zealand (1-0), England (2-0), Australia (1-0), New Zealand (2-0) and Pakistan (3-0).
However, as these series are now only weighted at 50 per cent, it has dropped four ratings points to slip from 127 ratings points to 123.