Smith was on 54 at the break, with Peter Handscomb on 16 and the home side having set a good platform before the trickier final session under lights.
Smith was dropped in the final over of the session, with part-time spinner Azhar Ali coaxing an edge to Sarfraz Ahmed but the wicketkeeper put the chance down.
Pakistan's bowlers had earlier taken two quick wickets before the tea break to slow Australia's charge after the home side's openers dominated the opening session.
Smith won the toss, his first in seven matches, to put his team into bat and openers David Warner and Renshaw moved serenely past 50 on a benign pitch that initially offered little for the bowlers.
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Paceman Mohammad Amir struck to remove Warner lbw for 32, ending a 70-run opening partnership and leg-spinner Yasir Shah had number three batsman Usman Khawaja caught for four.
Khawaja fell for a leg-side trap, spooning a simple catch straight to Misbah at short midwicket.
Australia were unchanged from the side that defeated South Africa in the dead rubber test in Adelaide, with spinner Nathan Lyon retained along with the pace trio of Mitchell Starc, Josh Hazlewood and Jackson Bird.
Misbah and Yasir returned to the side for Pakistan after missing the second test against New Zealand in Hamilton.
Both teams entered the three-match series in uncertain form, with a rebuilding Australia beaten by 2-1 against South Africa, but reversing their slide with a comprehensive win in the day-night test at Adelaide Oval.
Pakistan lost 2-0 in New Zealand and are bidding to win their first series in Australia.
(Reporting by Ian Ransom in Melbourne, editing by Nick Mulvenney/Sudipto Ganguly)
