Following on from Shane Watson’s redemptive 176 on day one, Smith made 138 not out to steer the tourists to 492 for nine declared at the Kia Oval.
But in order to turn that total into a winning position Australia need England’s batting to fold, with Alastair Cook (17no) and Joe Root (13no) unwilling to oblige in the evening session.
The hosts, who have already wrapped up the series by going 3-0 up at Durham, reached 32 without loss when bad light brought things to a close.
With rain washing out the morning session and costing spectators 27 overs, Australia may now need to force the game to set up a result.
If weather intervenes again, as it is forecast to do tomorrow, a triumphant series for Cook’s side could have a regrettably low-key finale.
Regardless of the result, Smith will take great heart from his first Test ton and will approach the return series this winter with renewed confidence.
The same cannot be said of England’s surprise debutants in this match, Chris Woakes and Simon Kerrigan. Having been mercilessly bullied by Watson on Wednesday, slow left-armer Kerrigan was not asked to bowl again and seems further away from a winter tour than he was at the start of the week.
Woakes did manage to celebrate a first wicket at the highest level, that of Australian newcomer James Faulkner, but figures of one for 96 in 24 overs do not bode well for the Warwickshire all-rounder.
The Australia innings had resumed on 307 for four, with the tourists adding 185 runs in 38.5 overs and losing five wickets.
Much as Watson’s muscular effort had dominated the opening day’s play, Smith’s knock was the central pillar here.
Having compiled a low-key half-century in Watson’s shadow, he stepped into the limelight with aplomb.
He lost his first partner soon after play got under way, James Anderson clipping the top of Peter Siddle’s off stump with a glorious delivery that was wasted on a nightwatchman.
That brought Brad Haddin to the crease and he shared a busy stand of 65 with Smith, sapping much of England’s enthusiasm.
Smith was in full control of his game, a fact proven by one brutal stroke through point off Stuart Broad.
Woakes, thrown back into the action by Cook after a troubled baptism, had a decent lbw shout against Haddin early in his first spell but otherwise it seemed a batsman’s game.
England’s frustration manifested itself first in a spurious DRS referral that even the bowler, Anderson, appeared dubious about and then with the introduction of Jonathan Trott.
When England named their new five-man attack, Trott must have felt his occasional swingers would not be required and Smith was not going to miss out when they were.
He had 94 to his name when he clattered Trott back over his head for six, reaching three figures in the best possible style. It was, possibly, the last moment of authentically good cricket in the innings.
First Haddin dragged Trott on for 30, giving him an unexpected fifth wicket at this level, then a messy hour of play unfolded after tea. With Australia looking to score quickly to force the game England slowed their over-rate to a crawl, instructed their bowlers to work defensive lines and at times had every fielder on the boundary.
Faulkner (23), Mitchell Starc (13) and Ryan Harris (33) all scored cheap runs with gusto, while Smith made his way to 138no. Faulkner’s dismissal at least gave Woakes a first Test wicket, Trott holding on well to a mis-hit hook.
Graeme Swann, after three hours wandering the outfield, was finally called to bowl at 5.30pm and promptly cleaned up Starc with his second ball.
Clarke called his side in after Anderson charged 20 yards to claim Harris caught and bowled, finishing with four for 95.
Australia would have been hoping for swift inroads at the head of the innings and Clarke was quick to get all of his seamers involved. Cook and Root shared four boundaries before gladly leaving the field when the darkness drew in.