Four-time world champion Australia had started the series in third position on 114 ratings points and has now finished on equal points with India on 117 ratings points.
However, when the ratings are calculated beyond the decimal point, Australia is 0.2 clear of India and five ratings points clear of South Africa, which has dropped one place to third.
South Africa had moved ahead of Australia last month, following its 2-0 victory over New Zealand.
World champions India though will have a chance to come back to the top spot in the triangular series, also featuring Australia and England starting in Melbourne on January 16.
With just one ranking point separating them, fourth placed Sri Lanka hosts fifth placed England in a seven-ODI series which starts in Colombo on Wednesday.