A thrilling climax to a wonder­ful series put the exclamation mark on a stunning season for Irish rugby. Ireland were clinging on for dear life, and had to go through the ordeal of a late TMO referral but a first series win against a southern hemisphere superpower for 39 years is theirs. Just.

Johnny Sexton’s nerveless late penalty had secured a four-point lead and the Wallabies came forward in waves, but Ireland held firm. They collectively held their breath with the clock red but when the ­television match official, Ben Skeen, could see no “clear and obvious” knock-on from Jacob Stockdale the celebrations could begin. A Six Nations grand slam, Leinster’s historic domestic and European double and now this. Make no mistake, it is Ireland who pose the greatest challenge to New Zealand at the World Cup next year.

A cagey first half in which both captains – first Australia’s Michael Hooper then Peter O’Mahony of Ireland – went off through injury was followed by a breathless second. Ireland got the cushion they sought with CJ Stander’s 43rd-minute try but back Australia came with a stunning score from Marika Koroibete.

Had Bernard Foley’s penalty in the 67th minute not slid by it was hard to see Ireland rousing themselves again – on such small margins are series such as these decided – but the ­character displayed by Joe Schmidt’s side, ­having lost the first Test in Brisbane, means they are worthy winners. They led 12-9 at the interval – Sexton ­kicking four penalties – but it ought to have been more.

Ireland were late arriving to the ground, their bus held up, just as it had been at Murrayfield last year, but whereas previously that led to a sluggish start Schmidt was in no mood for a repeat. David Pocock was at his disruptive best at the breakdown but Ireland were in the ascendancy for most of the half, winning the collisions and dominating territory. Stockdale was sent to the sin-bin for an elbow to Nick Phipps’s throat but still Ireland were on top, all the more so when Israel Folau was shown a yellow card for an aerial clash with O’Mahony, which ended the Ireland captain’s match.

Stander’s try then put Ireland eight points ahead and while Sexton’s missed conversion was uncharac­teristic, his shrewd kick that led to the score certainly was not. He spotted the space on Australia’s right, found it with unerring accuracy and after a couple of subsequent penalties were kicked to the corner Stander was driven over.

Ireland appeared ready to race through the gears at that point but almost immediately the petrol light came on. Australia rallied and they, too, kicked a series of penalties to the corner. They could not drive over but after showing great patience to stretch the Ireland defence Foley’s diagonal grubber kick was perfectly weighted for Koroibete to score. Stockdale was again caught out of position – he has not had the best of series defensively.

Foley added the conversion and Ireland’s lead was just one point. The failed penalty attempt was out on the right but he will know the significance of his miss considering Ireland’s fatigue at that stage. He does not carry the can alone, however, for discipline was a problem again for Australia and by conceding another penalty in the 79th minute they allowed Sexton to ensure the Wallabies needed a try with their last attack.

Folau gathered the restart and they cranked up the pressure but as they closed in down the right Foley’s pass was wayward and not, ­according to the TMO, because of an intervention from Stockdale – drama till the last.

In truth it would have been rough on Schmidt’s side, for throughout the series Australia have not been as fluid with ball in hand as they can be, but this is not an Irish side who entertain the idea of gallant defeats. It was confirmed last week that the All Blacks will visit Dublin in the autumn – it is not to be missed.