Two in a row. It really doesn’t seem like too much to ask. But for a team that has yo-yoed between dynamic and diabolical performances for decades, it is paramount that Australia beat Wales and notch back-to-back wins. Having snapped a three-game losing streak with victory at Twickenham, they must now back it up in Cardiff.

With their stirring last-gasp victory over England in game one of their grand slam tour, the Wallabies lit a fire under sports fans of all ilks. NRL fans are, of course, claiming credit for Joseph-Aukuso Suaalii’s heroics, and idle AFL and football aficionados are remembering the glory days of the ‘90s and naughties when the men in gold were Australia’s favourite team.

Related: Suaalii dropped from Australia’s starting XV against Wales in Cardiff

It was a great Test between two nations that have been the best of enemies for 115 years – 10 tries, a lead that changed five times, and a boilover 42-37 result at the home of rugby. For weary fans hungry for a side to believe in, and an administration desperate to claw their way out of $80m debt and condone spending $5m on Suaalii, it was a triumph in every sense.

The victory not only gave Wallabies bragging rights but kept alive the 40-year fever dream of winning a grand slam for the first time since 1984. Suddenly, with Suaalii sprinkling his stardust, Australia played like world-beaters and won with exactly the kind of tough, brilliant and breathtaking rugby their forebears made famous.

Good as it was, coach Joe Schmidt will know it wasn’t perfect. The Wallabies were beaten at the jump and down 15-3 in the first quarter, before fighting back to 28-18 half an hour later. Nor did the superlatives about debutant Suaalii hide four missed tackles and a paltry eight metres from seven carries, albeit with four sublime offloads and three kickstart intercepts.

Wales is the banana skin game for the Wallabies, the fixture everyone predicted they’d win. Strut into Principality Stadium too cocky and Australia risk slinking out as beaten favourites. England’s pre-game braggadocio came back to bite them last weekend and Schmidt must ensure his men don’t make the same mistake against Warren Gatland’s wounded Welsh.

“Repeatability is the biggest thing,” affirmed halfback Tate McDermott, who is in line to repeat last week’s star turn off the bench. “Backing up the performance against the English is crucial for us. It’s a fresh page. Last week was a great moment [but] it’s irrelevant because we’ve got a fierce Welsh team in our face and we’ve got to make sure we’re ready.”

The national emblem of Wales is the leek. However, the fact Australia leaked 37 points against England and 44 across the 25-16 and 36-28 wins over Wales in July, gives Gatland hope. The loss to Fiji last week was Wales’ 10th consecutive Test defeat. But Fiji and Wales both beat Australia in France and only late tries got Schmidt’s men over the line in the July series.

Even so, it seems Schmidt is determined to give everyone a chance ahead of the British & Irish Lions tour next July. Having surprised everyone by promoting Suaalii to the starting XV last week, he has shocked again by benching his new star and trialling 49-Test veteran Samu Kerevi alongside Len Ikitau in the centres despite Kerevi, now 31, not playing a Test in over a year.

The other curious switch is Will Skelton displacing Jeremy Williams at lock. Williams played the finest of his nine Tests last week, with his spectacular try in the corner crucial to getting Australia in front. Yet Schmidt has called in the 32-year-old behemoth from club duties at La Rochelle to gauge what his 203cm frame and 145 kg of heft can offer.

Related: Joseph-Aukuso Suaalii: from unproven prospect to living out a dream on rugby’s grandest stage

Three more changes have been forced on Schmidt, with skipper Harry Wilson sidelined due to concussion and winger Dylan Pietsch out with a calf injury. Taniela Tupou – who was sub-par against England and seems hobbled by the knee injury he suffered against the All Blacks – is also out, with veteran prop Allan Alaalatoa to start and also captain.

Pietsch’s injury opens the door for Max Jorgensen to join the run-on side after diving over for the winning try against England. It reunites the back three of fullback Tom Wright and No 11 Andrew Kellaway whose brave running sparked the three vital comebacks against England. Schmidt’s faith in the trio is paying off with all increasingly confident to attack from anywhere.

That credo propelled the 1984 grand slam Wallabies to glory and it’s the attitude that now gives the 2024 Wallabies a shot at history. Beat Wales and world No 6 Scotland are ripe for an upset, setting up a showdown with Schmidt’s old side Ireland to sweep the home nations. For a rugby nation too long written off as easy beats, that would be a warning to the world.

But forget about four from four for now. First the Wallabies must make it two from two.