Opener Imamul Haq hit a fighting half-century to take Pakistan to 136-2 at lunch on the final day of a delicately poised deciding third Test against Australia in Lahore on Friday.

Haq was unbeaten on 66 and skipper Babar Azam on 19 as Pakistan added 63 runs to their overnight score of 73-0 in the extended two-and-a-half-hour session due to Friday prayers.

The home team, set a challenging 351-run target, need another 215 runs to win the Test or bat out another 57 overs to ensure a draw on a Gaddafi Stadium pitch that has started to take sharp turn.

Haq has been rock-solid, having so far hit five boundaries in his fourth Test half-century. He added 31 for the unfinished third-wicket stand with Babar.

Australia could have had dangerman Babar run out on 16 when in an attempt to take a sharp single he was sent back by Haq, but bowler Nathan Lyon fumbled Travis Head's throw from the covers.

With the series on the line after the first two Tests ended in draws, Australia attacked from the start with skipper Pat Cummins and Cameron Green on the charge.

Green provided Australia the much-needed early breakthrough when he forced an edge off Abdullah Shafique in the fourth over of the day for wicketkeeper Alex Carey to take a simple catch.

Shafique failed to add to his overnight score of 27.

Haq and Azhar Ali took the score to 105 when spinner Lyon struck. Azhar missed a sweep and the ensuing thin edge was taken in the slip by Steve Smith.

Umpire Ahsan Raza was forced to overturn the not-out decision on Australia's review with television replays showing a faint edge from the bat.

Australia are touring Pakistan for the first time since 1998, having previously refused to visit over safety fears.