Pakistan survived an intriguing last session to reach 73-0 on day four after a bold declaration by Australia set a tricky target of 351 runs in the series-deciding third test on Thursday.

Opening batters Imam-ul-Haq, 42 not out, and Abdullah Shafique, 27 not out, survived television referrals against offspinner Nathan Lyon to leave the home team still needing 278 runs in a minimum 90 overs on the last day Friday.

Shafique had a close escape when Steve Smith's poor run in the slips continued as the Australia vice-captain couldn't hold onto a sharp chance off Marnus Labuschagne's penultimate ball of the day.

Captain Pat Cummins declared Australia's second innings at 227-3 shortly after tea, Usman Khawaja having achieved an unbeaten 104, his second successive century to round off a brilliant tour to the country of his birth.

It gave Australia nearly four sessions to have a crack at Pakistan, after missing out in the second test at Karachi where Pakistan batted for 171.4 overs and forced an epic draw.

The worn-out pitch at Lahore encouraged Cummins after Pakistan collapsed to 268 in the first innings against the brutal reverse swing of Cummins and Mitchell Starc to concede a massive 123-runs lead.

Khawaja featured in three half-century stands and raised his hundred at the stroke of tea as Australia blunted the reverse swing of Naseem Shah (1-23) and Shaheen Shah Afridi (1-45) while scoring freely against spinners Nauman Ali and Sajid Khan.

Khawaja made 97 in the drawn first Test at Rawalpindi and followed with 160 and 44 not out at Karachi. Despite being ill on the opening day of this test, Khawaja scored 91 in the first innings. The left-hander has an impressive 496 runs at a series average of 165.33.

Khawaja combined in a 96-run opening stand with David Warner, who was clean bowled on 51 by Afridi in the penultimate over before lunch.

Labuschagne, with 36, then shared another brisk 65-run stand with Khawaja before he swept hard at left-arm spinner Nauman and was caught at deep midwicket in the second session.

Read: Australian cricket team arrive in Pakistan after 24 years amid tight security

Smith scored only 17 but on 7 became the fastest batter to 8,000 test runs in his 151st inning, one quicker than former Sri Lanka skipper Kumar Sangakkara. Naseem found the outside edge of Smith's bat soon after tea.

In an eventful morning session, Pakistan missed out on dismissing Warner early; Khawaja escaped on 31 after he was bowled off Naseem's no-ball and then umpire Aleem Dar was involved in an animated conversation with Warner likely about how and where the veteran was running on the deteriorating pitch.

Warner even removed his helmet and gloves, exchanging words with Dar before play resumed after nearly three minutes.