Mitchell Starc was on 12 and skipper Pat Cummins four as Australia reached 449-7 in reply to Pakistan’s first innings total of 476-4 declared.
But Smith was annoyed with himself for getting out earlier on 78.
“I got a bit greedy with the field they had set. I had worked pretty hard and got myself in a nice position to go on and get a big score.”
Australia are on their first tour to Pakistan since 1998, having previously refused to visit over security fears.
Despite no rain forecast for Tuesday, the likelihood of a result in the opening match of the three-Test series looks bleak, barring a Pakistan batting collapse in the second innings on a wicket that still looks full of runs.
Smith believes there would have been a small chance of a result on the final day if not for the hours of play lost to the weather.
“Perhaps if we were five down we might have been able to push a little harder in the morning and potentially set something up for the fourth innings,” he said.
But the pitch at Rawalpindi Cricket Stadium has produced 925 runs for just 13 wickets, and is unlikely to yield the spin needed for a result.
Still, Pakistan grabbed five wickets Monday, including that of top-ranked Test batsman Marnus Labuschagne (90) and Smith, with Nauman taking 4-107 in 37 precise overs.
Nauman broke a stubborn fifth-wicket stand of 81 between Smith and Cameron Green (48) by having the young all-rounder caught off a miscued sweep at leg slip by Iftikhar Ahmed.
Australia were looking for quick runs to go ahead in the first innings, but they were further jolted as Nauman dismissed Smith off a mishit sweep that caught the gloves and landed in wicketkeeper Mohammad Rizwan’s safe hands.
Smith batted two minutes short of five hours, hitting eight boundaries.
Alex Carey made 19 before he was bowled by quickie Naseem Shah in the fading light.
Earlier, overnight rain had left the outfield at the stadium waterlogged and the umpires only allowed play to start after lunch.
Australia, 271-2 overnight, progressed to 288-2 when Pakistan took the second new ball after 80 overs — and were instantly rewarded.
Left-arm paceman Shaheen Shah Afridi forced an edge off Labuschagne which Abdullah Shafique took diving to his right in the slips.
Labuschagne lasted 190 minutes during which he hit 12 boundaries.
Travis Head, fresh from being man-of-the-series in Australia’s 4-0 Ashes win back home in January, hit two boundaries before he miscued a drive off spinner Nauman and was caught behind by Rizwan.
Shaheen (1-80), Naseem (1-89) and Sajid (1-122) were the other successful Pakistan bowlers.
The second Test of the series is in Karachi from March 12-16 and the third in Lahore from March 21-25.