Pakistan's savage four-word sledge after Steve Smith nightmare

Pakistan Cricket's official Twitter account has brutally mocked Steve Smith after the Aussie vice-captain endured a nightmare in the field on day four of the second Test.

Australia need eight wickets to win on the final day in Karachi after a brilliant century from Pakistan captain Babar Azam on Tuesday.

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After Pat Cummins set Pakistan an improbable 506 runs to win, the hosts went to stumps at 2-192 with Azam unbeaten on 102 and Abdullah Shafique not out on 71.

The Aussies endured a frustrating day in the field, with Smith missing a number of crucial chances.

The former Aussie captain put down a sharp chance at first slip when he dived across in front of wicketkeeper Alex Carey after a nick from Azam.

Smith also put down a difficult catch off the bowling of Mitchell Swepson in the first innings, but his third drop was as straightforward as they come.

Shafique edged a Pat Cummins delivery straight to Smith at wide first slip, but the 32-year-old inexplicably shelled the regulation catch.

Commentators and fans were left in disbelief, with Pakistan's Twitter account sticking the boot in.

The hosts tweeted a video of Smith's three missed chances, writing: "Don't mind the spill".

Aussies chasing eight wickets on final day in Karachi

Cummins' tactics have been scrutinised throughout the fixture at Karachi's National Stadium, a venue where Australia have never won in eight previous Tests.

Did Cummins bat too long as Australia's first innings of 9(dec)-566 stretched through 189 overs and into day three?

Why didn't he enforce the follow-on after skittling Pakistan for 148?

Will he regret extending Australia's second innings for 35 minutes on day four, when they already held a whopping 489-run overnight lead?

Victory will justify all decisions, but the outcome is likely to hinge on the first session on Wednesday's final day, according to Australia's batting coach Michael Di Venuto.

Cummins and his bowling colleagues will begin the day with a ball just two overs old.

The Australians expect the ball to reverse swing about 20 overs in, before the leather becomes softer and easier for batsmen to handle.

"Both while it's shiny in the first few overs and when reverse swing comes in probably 20 overs in," Di Venuto said after day four.

"With the harder ball, that is going to be a critical period of play for us," .

Australia never expected to rip through Pakistan's batting line-up as they did in the first innings, but they did expect the National Stadium pitch to play more tricks than it did.

"When the ball was hard and reversing, we got a couple of breakthroughs and were able to put a hole in them as far as wickets," Di Venuto said of Pakistan's first innings.

"Today they got through that period. The ball softened, 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 a bit more variable bounce."

with AAP

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