Pakistan went down by just 39 on the back of Asad Shafiq's magnificent fighting 137 batting with the tail.
Pakistan, faced with a massive 490 runs to win the day-night Test, went down by just 39 on the back of man-of-the-match Asad Shafiq's magnificent fighting 137 batting with the tail.
Until Shafiq was undone by a rising Mitchell Starc delivery, Pakistan looked to have every chance of shattering the record for the highest fourth innnings run chase to win a Test -- the 418 for 7 made by the West Indies against Australia in Antigua in 2003.
Smith became a fraught captain trying to think of ways to stop the Pakistani juggernaut from claiming a stupendous win against the odds after trailing Australia by 287 runs on the first innings.
"Probably with about 60-odd runs to go I started getting a little bit nervous, hoping that one of our world-class fast bowlers would be able to step up and get us that breakthrough," Smith said.
"Thankfully, Mitchell Starc was the one to do it today. Things got a little bit close for my liking.
"But you always have to keep the faith and try and keep the guys in good positive spirits and know that when you're eight down you are really one wicket away from closing the game out."
For much of Monday's extended opening session Pakistan, who began with just two wickets left and 108 runs needed, looked more than capable of holding off Australia's attempts to end the match.
"To get one to bounce the way he did, with the pink ball being 60 overs old, not really doing much, and get us that key scalp, a lot of credit has got to go to Mitchell," the skipper said.
Starc's brutish lifter came off the shoulder of Shafiq's bat and lobbed to David Warner in the gully for the match-turning catch.
Smith confessed he had to work harder on his fielding after dropping two catches at crucial stages in Sunday's marathon three-hour night session which had given Pakistan momentum.
"Maybe I need a slips cradle for Christmas or something like that to work on a few things," he said.
"I do pride myself on my fielding and it was disappointing to have dropped a couple of catches last night and allowed the Pakistanis back into the game.
"Things could have certainly happened a lot quicker had I held onto those.
"I need to continue to work hard as the leader of this time on my fielding. We set high standards as a team."
Smith also said he wanted to come off and not play the extra half hour on Sunday night to force a result.
"The umpires deemed for it to be the opportunity for a result. We went with that," he said.
"I probably then would have liked to come off and given our bowlers a rest -- they'd worked incredibly hard all day and Pakistan were just starting to get onto a bit of a roll -- but you've got to go with the umpire's call.
"It was their decision out on the ground, and they decided to stay out there."