The record for the fastest Test hundred in terms of balls faced was set by West Indian legend Viv Richards, against England at Antigua in 1986, who also took 56 balls.
Pakistan set a mammoth 603-run target for Australia to win the second Test and save the series after declaring their second innings on 293-3.
Azhar Ali scored 100 not out while Misbah-ul Haq was unbeaten on 101, setting a new world record for the fastest Test half-century off just 21 balls and equalling the fastest century record of 56 balls.
That put Pakistan well on course for a 2-0 series win after winning the first Test by 221 runs. Pakistan have not beaten Australia in a series since their 1-0 win at home in 1994.