Pakistan, chasing 180 for victory, reached 140 for three in 37 overs to edge nearer to their first Test victory over the Australians in 15 years.
A Pakistan win would also deny Australia an eighth straight Test win.
Azhar Ali was 47 not out and Umar Akmal [ Images ] was on two when the players left the field despite bright sunshine.
Left-arm fast bowler Doug Bollinger claimed the late wickets of Farhat, who was bowled, and Umar Amin for a duck. Both wickets fell caught behind with the score on 137 to give Pakistan a glimmer of hope.
Earlier, Steven Smith scored a maiden half-century as his late assault on the Pakistan bowling helped Australia set a competitive target of 180 for Pakistan to win the second Test at Headingley on Friday.
Australia were bowled out for 349 on the stroke of tea on the third day, as number eight batter Smith butchered 77 in 100 balls.
He began slowly but eventually smashed nine fours and two sixes, including two in succession off leg-spinner Danish Kaneria with the latter finding the roof of the rugby ground stand.
Smith was the last man out, bowled by Umar Gul.
Australia lost key wickets throughout the day in pleasant batting conditions but managed to eke out enough runs to set up what is likely to be a nervous chase for Pakistan, who have not beaten Australia in a Test for 15 years and must win to draw this two-match series.
Australia's battling effort, after they were dismissed for a 26-year low 88 in the first innings, has given genuine hope of an eighth straight Test win.
Mohammad Aamer [ Images ], the 18-year-old left-arm pace bowler, claimed all three wickets of the morning session and he finished with four for 86 as Australia's last five wickets raised 185 valuable runs.
Skipper Ricky Ponting [ Images ] was out for 66 in the third over of the day when he chased a wide Aamer ball.
The failure to finish off Australia's late order was a major frustration for Pakistan who saw Smith slap boundaries viciously off Asif and Gul through midwicket.
The various momentum swings were appreciated by a crowd that had swelled from the first two days when empty seats were widespread at the neutral venue. The East Stand was two thirds full as fans basked in the sun -- a far cry from the overcast conditions of the first two days.
Earlier, spectators were oblivious to a power cut that struck the town of Headingley, jamming the scoreboard on 179 for five, the Dickie Bird [ Images ] clock stopped at 11.46 and television monitors around the ground halted, which may have made for interesting times had the third umpire been asked to adjudicate on a possible dismissal.