At the end of a hard day of toil in the fifth and final Test for Joe Root’s men Smith was unbeaten on 44, having shared a 107-run partnership with Usman Khawaja (91no) for the third wicket.
Australia were 193-2 trailing England’s first innings 346 all out by 153 runs with eight first innings wickets in hand.
Hopes of a long overdue victory to mark Root’s first Ashes tour as captain already appear to have receded into the distance with Smith’s men looking highly likely to post a first innings lead.
And it could be a big one, too.
Yet realistically England were in trouble when they started the day five down for 233 after winning the toss and batting.
And even a flourish from their long tail which got them 113 further on for the loss of the last five never looked enough on a pitch which held few terrors.
Dawid Malan had resumed with Moeen Ali on 55 but was only able to add another seven to his overnight total before he was dismissed by Mitchell Starc.
While the bowler provided the canvas it was Smith with an astonishing one handed diving grab at second slip who created the masterpiece.
Frustratingly for Smith his troops were unable to replicate his efforts proceeding to offer up two chances for Tom Curran on 21, spilled at mid on by Pat Cummins, and to Moeen on 22, who was reprieved by a howler from Josh Hazlewood at mid-on.
Those two blunders were to cost Australia 26 runs as Curran and Moeen put on 43 and then Stuart Broad combined with the former to add a further 41 including four fours and two sixes, both from Broad hooks.
Broad’s muscular cameo helped Engalnd to 346-9 before an attempted on-side heave top-edged to a backpedalling slip.
The innings was wrapped up with a mix-up between Mason Crane and Jimmy Anderson without another run being scored.
England got off to the perfect start, Broad knocking back Cameron Bancroft’s middle and off stump in the second over but David Warner (56) and Khawaja steadied the ship.
Then Smith and Khawaja added over a century without too many worries. The only chance given came off the edge of Smith’s bat from Broad but the ball carried wide of Jonny Bairstow and short of Alastair Cook at second slip.
One positive for England was the debutant Mason Crane who bowled with confidence if without reward. HIs 17 overs went for 58. Anderson was the pick of the England attack with 1-25 from 14 overs.