How did Australia go from India to this? From a triumphant win in Pune six months ago to a demoralizing defeat in Mirpur today? From their first Test victory in India in 13 years to their first Test loss to Bangladesh in, well, ever? Those are the questions captain Steven Smith and coach Darren Lehmann must ponder after Australia fell 21 runs short of their target and set themselves on the precipice of a possible plummet to sixth in the Test rankings.

It is true that the Mirpur pitch turned and offered variable bounce, but what else would Australia have expected? In similar conditions in Pune - albeit with the benefit of batting first - they thrashed India by 333 runs, thanks to a 12-wicket haul from Steve O'Keefe and a second-innings century from Steven Smith. So, aside from Bangladesh playing well, what went wrong for Australia this time?

"I think we made a few errors, a few guys getting out in ways they've got out before and not learning from the mistakes, which was a bit disappointing," Smith said. "You've got to keep trying to learn and keep trying to get better in these conditions. It's a difficult place to play when the ball is spinning from ball one of the game but both teams were on the same wicket.

"We just weren't good enough on this occasion. The batting in the first innings let us down but the partnership between Shakib and Tamim as well, that was a big turning point in the game. We had them under a bit of pressure at one point at three for not many and we just weren't able to break that partnership."

One notable difference between Australia's campaigns in India and Bangladesh has been their relative lack of preparation for this tour. Ahead of the India series, Australia spent two weeks at a training camp in Dubai, and when they arrived in Mumbai they had a first-class practice match against India A.

Their preparation for this trip has involved a training camp in Darwin, but their scheduled two-day warm-up game in Bangladesh was washed out and they had no match practice ahead of the first Test. There was also the matter of Australia's downtime over the winter, while the pay dispute was simmering away.

"We didn't have a tour game but I'm not making an excuse for that," Smith said when asked if Australia could have prepared any differently. "The facilities we had here in the nets were fantastic to be fair, the wickets were really good. They took quite a bit of turn and it was good practice. I've got no excuse there.

"Guys just needed to be able to adapt a little bit better, particularly in the first innings. Second innings runs are so difficult to get in the subcontinent and you've really got to make the most of the first innings and we weren't able to do so."

The loss has left Australia needing a win or a draw in the second Test in Chittagong to avoid falling to sixth in rankings for the first time since the system was introduced in 2003. Still, an Australian win in Chittagong will leave Smith's side in fifth place, and he conceded it was hard to argue that Australia deserved to be ranked any higher.

"I don't know if we're better than that at the moment, that's a difficult question," Smith said. "I think we're still a young team, obviously some new players that have come in only last year in the summer and some guys that are still trying to find their way. We're a young team and we're a team that hopefully is going to continue to improve.

"I thought we made some really good strides in our last tour to India, albeit we lost that series. We've still got a long way to go to rise up in the rankings and hopefully as a group we can continue to improve and get better."

Improving together is something Bangladesh have certainly managed. For the first decade and a half of their existence as a Test side they beat only Zimbabwe and a second-string West Indies side, but they have now won Tests against Australia, England and Sri Lanka in the past year. Smith said it was obvious that Bangladesh were a threat at home.

"They've certainly come a long way over the last couple of years," Smith said. "I think they're a dangerous side, particularly here at home as we've seen. They've just beaten us, they obviously beat England not too long ago, so they're a team that's confident in these conditions.

"They've got some good players. I thought Tamim Iqbal looked very good at the top of the order, chanced his arm and played some good aggressive cricket. Shakib played particularly well in the first innings and bowled well in both innings as well, so their experienced players really stood up in this game for them. I thought they played very well."

The side is likely to strongly consider adding an extra spinner to their attack in Chittagong after Josh Hazlewood suffered a side injury mid-match in Mirpur. Steve O'Keefe has been added to the squad and could be rushed straight in to bowl alongside Nathan Lyon and Ashton Agar, which would leave Pat Cummins the lone fast bowler. Allrounder Hilton Cartwright could be considered as a backup seam option, possibly at the expense of Usman Khawaja.