Dubai: Younis Khan became Pakistan's most prolific Test century-maker and also the first batsman in more than 40 years to post twin centuries against Australia, as Pakistan set Australia a distant 438 to win in Dubai.
Australia will need a last-day miracle if they are to avoid defeat in the first Test against Pakistan after a dramatic collapse late on day four.
The tourists lost four wickets for five runs in the space of four overs and finished the day on 4-59, trailing by 379 runs.
Earlier, Pakistan had declared following star veteran Younis Khan's second century of the match.
Younis became the first man in more than 40 years to score twin centuries against Australia. The last was Black Caps opener Glenn Turner in Christchurch in March 1974.
Pakistan captain Misbah-ul-Haq declared at 2-266, leaving 23 overs for the Australians to negotiate before stumps.
That Australia could only take two wickets on day four would be a matter of some concern before next week's second Test in Abu Dhabi, but of more pressing concern would be the imposing target.
History is against Australia, and it would take a new world record to achieve victory. The current best fourth-innings score to win remains the West Indies 7-418 against Australia in 2003.
Australia's best fourth-innings winning total was the 3-404 against England at Leeds in 1948, when Sir Donald Bradman hit an unbeaten 173 to secure the win.
Pakistan - 454 (Sarfraz 109, Younis 106, Asad Shafiq 89, Johnson 3-39) and 286/2 (Shehzad 131, Younis 103*)
Australia - 303 (Warner 133, Yasir Shah 3-66) and 59/4
Status - Australia need 379-runs to win