Steven Smith's mastery shines a harsh light on the rest of Australia's batting order

For a second or two after Steven Smith shuffled across and missed the first ball of a Chris Woakes spell in the final hour at The Oval, 24,000 people suspended their disbelief. So impassable for so long, and so seemingly impervious to the ball that optically looks as though it might best dismiss him, Smith had fallen lbw in a remarkably nondescript fashion. There was as much surprise as there was delight in the subsequent roar from the crowd.

A score of 80, dropped once on 66 by Joe Root off Sam Curran, was in actual fact Smith's lowest score of an incredible series, which to date has reaped him 751 runs in six innings. He will return to Australia at the end of this tour as both a hero and an undisputed genius, and the main reason why, for the first time since 2001, the men in baggy green will have the Ashes in their keeping.

How much of a difference Smith had made to Australia's chances was writ large across a day that brought with it another definitive conclusion - this is an Ashes retention a world away from those of 1989, 1993, 1997 and 2001. On each occasion, Australia's batsmen dominated either for an entire series or at its critical junctures, and on each occasion the same preferred top six employed for the tour was able to turn out again, unchanged, for the first home Test of the following summer.

Here and now, however, only Smith and his erstwhile substitute Marnus Labuschagne have watertight cases to play against Pakistan at the Gabba from November 21. While the Australian tourists will go home with the satisfaction of a goal achieved, most of the batsmen among their number will not do so with a huge amount of comfort about the manner in which it has taken place. The numbers for the balance of Australia's batting line-up are eye-watering, meaning the celebrations that take place post-series will need to be tempered by plenty of uncertainty about what happens next for many of those involved.

Of the seven batsmen tried apart from Smith and Labuschagne, only Travis Head has managed to average better than 25 - something that made his omission for this Test a valid point to question. The only scores of 50 or better are owned by Head, Matthew Wade, and David Warner, and even then only once each. For Warner, it has been a tour of rare horrors, and by one measure unprecedented. No batsman in history has made more single figure scores in the one Test series than his eight out of nine innings so far.

This one ended no less wretchedly than others, though a little curiously as his abortive cut shot at Jofra Archer appeared to have daylight between the bat and the ball when Warner was deemed to have nicked it. Warner will doubtless be hoping to reacquaint himself with his beloved Kookaburra ball, the better for clattering pickets with it on friendlier home surfaces, but he would not want to start the domestic season slowly.

"The thought of an Australian batting line-up in two years' time, on harder pitches against Archer's pace, is far less comforting for Langer than it should be"

Marcus Harris went next, edging a ball straightening up on him from around the wicket as now appears standard, giving him an average of less than half a run better than Warner's 9.33, albeit from three matches instead of five. These returns have been so poor as to make Cameron Bancroft's earlier contributions: 44 runs at 11, but facing 162 balls to Harris' 106, positively productive. As beautiful a player as Harris can be at his best, he has been unable to make a difference to the raging tide against Australia's left-handers this series. Nine Test matches in and he is still to make a century: a straightforward dropped catch in the day's final over off Josh Hazlewood will not help him either.

Labuschagne, as may have been expected, provided the only prolonged support for Smith. His innings was earmarked by pleasant strokeplay off his pads, though England's pacemen have gradually enjoyed more success against him in trying for lbw, as Archer eventually did after lunch. Well as Labuschagne has played in this series, he will be annoyed he has not capitalised on such sound starts with at least one hundred, but he can expect to be batting in the top order at the Gabba.

Of all the day's dismissals, that of Wade was arguably the most unfortunate. While his head position was not great, falling over towards the off side as Curran swerved the ball into him, the curvature of the delivery suggested that a not out lbw verdict would have been reasonable - something more or less backed up by the fact that ball-tracking had the leg stump only being shaved rather than squarely struck.

Even so, Wade has made precisely half his 220 runs in a single innings, making this a slimmer return than desired on the strength of the pre-Ashes run-making that had him jokingly referred to as "Don" by Australia A teammates a couple of months ago. Whether he is still a part of the team at home may well depend on whether the selectors choose to prefer the younger Alex Carey, who in terms of character and performance trends appears destined for a long career as a cricketer and possible leader for Australia, the major question being when he is introduced.

Mitchell Marsh, then, completed the top six, and initially looked to be doing better than he had managed in a dreadful run of performances in the UAE and at home against Pakistan and India last year. He defended stoutly, rotated strike and looked to punish the bad ball for 51 minutes, suggesting he was in decent fettle to help accompany Smith to his fourth century of the series.

However it was to a bad ball that Marsh fell, one of Archer's few poor ones to get a wicket over four matches. Short, down the leg side and not particularly dangerous, Marsh swivelled to dispatch it, only to pick out Jack Leach at fine leg. Australia's hopes of a substantial first innings lead evaporated there and then.

The rest were to be bewitched by Curran's swing - leaving plenty to rightly wonder why he had not been utilised by England earlier in the series - and then finished off by Archer's pace and a stunning final catch from Rory Burns. Joe Root's team enjoyed the sequence, not least Curran's two in two balls to defeat Tim Paine, nicking a good one that shaped in then seamed away, then pin Pat Cummins in front of all three stumps. Australia, it must be said, had done far better in far harsher conditions on numerous other days this series.

"I felt pretty good at the crease," Smith said, though he did admit to a touch of flu that may, at a pinch, have hampered his focus. "Unfortunately I couldn't bat with the tail for as long as I would've liked, but it was a nice little partnership with Pete and Nathan. It would have been good if I could have stayed out there a bit longer and done something similar to what Jos did for their tail, get the runs a bit closer together. But I felt pretty good again today."

An English victory here would make this the first tied Ashes encounter since 1972, and provide a reminder of the fine margins by which Australia retained the urn in Manchester. For Paine and Justin Langer, there is a reminder here that for all their good work over the first four Tests, this is not an Australian side that can afford to rest easy upon this achievement. The likes of Kurtis Patterson, Joe Burns, Will Pucovski and Matt Renshaw all have plenty of incentive to start next summer swiftly; Usman Khawaja's record at home virtually demands his recall.

And apart from anything else, Smith's dismissal and the collective failure of Australia's batsmen on a sun-dappled day in south London ensured that England will finish this series with the distinct feeling that they are not too far away at all from having the measure of the touring side. Right now the thought of an Australian batting line-up in two years' time, on harder pitches against Archer's pace, is far less comforting for Langer than it should be.