The hosts can no longer achieve a third 5-0 whitewash in England's last four visits, but after Smith's unbeaten 102, batting against type on a deathly slow pitch, they dashed any hopes of a consolation victory for Joe Root's men in this fourth Test and so stay 3-0 up with one to play.
Smith lost the assistance of an equally becalmed David Warner (86) in late morning, after Australia resumed still 61 in arrears with two wickets down, but he batted throughout the final day to steer Australia to the security of 263-4 to close out the draw 99 runs in front.
There was zero promise for England through the majority of the first session, as they failed to get the old ball off straight and there was precious little variable bounce either.
Root had already given Dawid Malan's part-time leg-breaks a run when he decided there was no harm in finding out if he himself could maybe turn the ball the other way.
Warner had spent more than five hours in stoic self-denial, no mean feat for a batsman whose career has been characterised throughout by attacking intent and flair.
The sight of Root's occasional off-breaks was too much, though, and he went after the first he faced – the Yorkshireman's second delivery in all – and paid the price.
Root pitched it perfectly into a foothold just outside the left-hander's off-stump, but Warner went after it all the same and managed only to skew a catch high into the safe hands of James Vince at extra cover.
Shortly afterwards, Smith followed Warner's slowest Test half-century with his own second-slowest – from 151 balls, 10 fewer than the opener – but when Shaun Marsh fell to a brilliant catch by Jonny Bairstow off Stuart Broad on the stroke of lunch, two wickets had fallen for six runs.
England therefore started the afternoon with renewed belief in the improbable, but Smith had other ideas.
Joined by Mitch Marsh, with whom he had put on a record 301 at the WACA, the world's number one batsman was on a mission to protect his team's series advantage.
Marsh needed 20 deliveries to get off the mark but, apart from squirting one thick edge just short of point, he was once again an able accomplice in his captain's plans as Australia comfortably negotiated the second new ball.
After two sessions, the statistics bordered on an uncanny symmetry as Australia went from 61 runs behind to the same number in front – off 61.1 overs.
It was an unfeasible crawl, Marsh playing his own manful part with 10 almost strokeless runs from 97 balls up to tea.
In what remained of the contest, more of the same followed – interrupted only by the highlight of Smith's century milestone, from 259 balls with six fours spread over almost seven hours – before an early close was mercifully agreed, with the home captain averaging 151.
*Australia have added spinner Ashton Agar to their squad for next week's fifth and final Test in Sydney.