Tom Curry and Sam Underhill had been hailed as the "Kamikaze Kids" by England coach Eddie Jones during the warm-up matches because of their desire to "hit everything that moves".
On Saturday night, pitted against two of the finest ever proponents of back-row play, the kids became men.
The pair delivered a lung-busting display, equal in its ferocious work-rate and physical relentlessness and true to the brilliant instincts of legendary duo Richard Hill and Neil Back, who were critical to England's World Cup triumph in 2003.
Curry was man of the match but it could easily have been Underhill, so central were the pair to England's blistering performance in the 40-16 win over Australia.
Australia have long been the leading proponents of playing two specialist opensides in the same back row but David Pocock and Michael Hooper, for years acclaimed for their breakdown brilliance and link play, were put in the shade by England's rookie pairing.
The decision by Jones to have faith in such an inexperienced combination appears to have been one of the greatest selection decisions of his four-year tenure. Having spent the first two years trying to unearth one openside, Curry and Underhill are proving the perfect combination.
Underhill's total of 20 tackles was more than twice as many as Hooper's, Australia's top tackler, who made nine, while Curry made 16 as England's fine defensive effort created enough pressure to run up a record score, despite their 34 per cent possession.
One of the standout moments was Curry's thumping tackle on Reece Hodge, to knock the wind out of Australia's attempt to play themselves back into the game after Jonny May's two tries in two minutes had given England control of the contest.
Moments earlier, he had helped create May's first try by drawing Hodge with a perfectly-timed pass.
"I play rugby for the physicality and when you get moments like that, it is special, especially watching Sam off the kickoffs, those big tackles he was putting in," said Curry.
"It is special to watch and encourages everyone.
"I would be a bit weird if I say making a tackle is more exciting than running with the ball. I don't think you start rugby to make tackles but, yeah, they are both pretty exciting.
"Whenever we play, we are always looking to get better. Our relationship grew [on Saturday], though."