Australia's No.1 ranking on the line

Just five days after being handed the ICC Test Mace as the No.1 Test team in the world, Australia's hold on top spot is already under threat following the first Test defeat at Pallekele Stadium.

Steve Smith and his men regained the top spot with a 2-0 series victory in New Zealand in February, while the annual rankings update at the annual cut-off date in April saw Australia extend their lead over second-placed India to six points.

In a competitive race to hold the coveted top spot, India are currently taking on the lowly-ranked West Indies in the Caribbean, while third-ranked Pakistan and fourth-ranked England are also going head-to-head.

Speaking at the mace presentation on Monday, where he also received an oversized cheque for US$1m (A$1.3m), Smith acknowledged the challenge his squad faced in maintaining the No.1 ranking.

"To be number one in the Test format is extremely satisfying and there's a lot of work to do to stay there," Smith told cricket.com.au.

"I place a pretty high importance on winning away from home, so this tour of Sri Lanka is going to be a tough one for us."

Having bowled Sri Lanka out for 117 in their first innings, Australia suffered a shock 106-run loss in Kandy. With the side likely to face more spin-friendly conditions in Galle and Colombo, we take a look at some of the many permutations and scenarios for the rankings that could unfold over the next few weeks.

Maximum points for England and India

The following scenario is based on England continuing their dominance from Old Trafford to beat Pakistan 3-1 and India going on to complete a 4-0 clean sweep against the Windies.

Sri Lanka win 1-0: Draws in Galle and Colombo would see Australia fall to third in the rankings.

Series drawn 1-1: If Australia can bounce back to level the series in one of the remaining two Tests, the tourists would hold on to top spot by a fraction of a rating point from India.

Australia win 2-1: If the Kandy Test was the wake-up call Australia needed and they respond with victories in the final two encounters, their hold on top spot would be secure, but narrow at just three rating points.

The Pakistan alternative

If Pakistan respond to their defeat at Old Trafford with consecutive wins at Edgbaston and The Oval to claim their series 3-1, while still assuming India beat the Windies 4-0, things change slightly for the Australians.

Sri Lanka win 1-0: Australia would still fall to third, with Pakistan the new world No.1 team.

Series drawn 1-1: Pakistan's gain in England would be too much for a drawn series in Sri Lanka to allow Steve Smith's team to keep their title, and they would be second, three rating points behind Pakistan.

Australia win 2-1: Only a series win for Australia in Sri Lanka would see them maintain the top spot, albeit narrowly over Pakistan.

India's rise to the top

For India to get to the top in Anil Kumble's first series as head coach, they would need to defeat the West Indies 4-0, rely on England winning their series against Pakistan and hope Sri Lanka don't win a another Test over Australia.

Surely not England?

If you're struggling with the thought of England moving back to the top of the world, take solace in the fact it seems highly unlikely. In the short term, that is.

England would first need to defeat Pakistan 3-1 and then hope for no more results in the Caribbean – so a 1-0 India win – and also no victories at all for Australia in Sri Lanka.

The Lankan factor

Worst case scenario for Australia is a fall to third, even if they lose all three Test matches in Sri Lanka. That would also push Sri Lanka up to sixth, above South Africa.

A 2-0 series loss would also see the No.1 ranking disappear, although it remains mathematically possible Australia could remain in second spot.