Ghosts of Sydney cast uneasy shadow over Australia's Karachi quest

An Australia win is still the favoured result in this Karachi Test, but as Babar Azam ended his wait for a century then walked off alongside Abdullah Shafique it was less certain than when they claimed the second wicket of Pakistan's innings shortly after lunch on the fourth day.

Eight wicket-taking opportunities (which then need to be taken) should be within Australia's grasp, but this is a scenario that has confronted them a couple of times in little more than a year, both times at the SCG, when they have been unable to secure victory by bowling out the opposition in the fourth innings.

In early 2021 they were denied by India - who then famously went on to take the series in the following game - and just a couple of months ago England clung on nine wickets down to take their only morsel of comfort from the Ashes. Against India Australia began the final day needing eight wickets and against England 10. While those SCG pitches did not break up, there were signs on the fourth day that the Karachi surface may not deteriorate quite as much as expected either.

In those Sydney contests, missed catches also ended up proving crucial in allowing the opposition to survive. Australia have shelled one in this innings when Shafique edged Pat Cummins to Steven Smith at slip. Smith was standing reasonably close, but it was a catch that should have been taken. Pakistan would have been 38 for 3 with Fawad Alam, on a king pair, next in and the ball starting to reverse.

"That's when reverse-swing was starting for us, the ball was quite hard, and yesterday that's when we got the breakthroughs," Australia's assistant coach Michael Di Venuto said. "It was a drop that we would have liked to have taken and Steve's got outstanding hands so it's a catch he would take 99 out of 100. It can be tough, the slips have to stand really close, and unfortunately on this occasion it went down.

"[Yesterday] when the ball was hard and reversing we got a couple of breakthroughs and were able to put a hole in them. Today they got through that, the ball softened and it doesn't do as much. We probably thought there might have been a bit more in the wicket today as far as spin and variable bounce [were concerned], but once the ball softens, there was occasionally, but those chances just didn't come for us."

Australia will believe that with another new ball (which is currently two overs old after Cummins took it in the closing moments), and then the opportunity when reverse-swing comes into play, that they can create the chances needed. However, it will also be a big day for the spinners. It would be unfair to place the burden of winning a Test match on debutant Mitchell Swepson's shoulders, but Nathan Lyon was the frontline spinner in both those Sydney Tests.

Across those two final innings against India and England he claimed 4 for 142 off 68 overs. This scenario, the fifth day of a Test on the subcontinent with a mountain of runs to defend, is what an experienced spinner should dream of.

He struck early in Pakistan's second innings when he undid Imam-ul-Haq for the second time in the match, this time angling a delivery into his front pad which would have smashed middle stump. Only Imam will know why he reviewed, and it may later have played a part in why Azhar Ali did not when it would have saved him against Cameron Green.

However, from then on, Shafique and Babar played Lyon with a reasonable degree of comfort. It was Swepson, with a few sharply-spun leg-breaks and later some turn from the footmarks outside leg stump, who caused more uncertainty. It could be especially challenging for the left handers who are to come in Pakistan's order but there remains the expectation that the quicks will be a threat.

"While [the new ball] is shiny…and when reverse swing comes in - 20 overs has generally been when it's started with the harder ball - will be a crucial period for us," di Venuto said.

Twenty-four hours ago Australia could barely have dreamed of the position they had put themselves in. It remains firmly in their grasp for a significant victory - just their third in Asia since 2006 - but tomorrow is a very important day for this evolving team.