The defeat was Australia's worst in 915 ODIs stemming back to 1971 and usurping the 206-run loss to New Zealand 32 years ago.
The commentators were eyeing England to clinch 500 as they only needed 50 in four overs to reach the score. England beat their own record (59) - jointly held along with Sri Lanka - which they achieved against Pakistan at the same venue in 2016.
The total of 481 for six was a new world record, while the 242-run margin of victory was the biggest in one-day internationals - not to mention the heaviest defeat for Australia.
While the innings of Hales and Bairstow, which both lasted 92 balls, laid the platform, skipper Eoin Morgan provided the late impetus with a rapid 67.
Australia could only make 239 all out, lasting just 37 overs.
Only details remained and they all favoured world No 1 side England who can therefore contemplate the possibility of a first 5-0 ODI whitewash of their Ashes rivals.More news: Messi cries for World Cup glory, Mum reveals
Captain Eoin Morgan joined in the fun as he struck a 21-ball half century - the fastest by an England batsman in ODIs - to become his country's leading one-day run scorer.
At the point when Roy was run out for 82 it conveyed Hales to the wrinkle and he set about the Australian assault with relish, striking 16 fours and five sixes of every a sizzling thump. On the sort of pitch that most batsmen would like to whisk to Paris for the weekend - and most bowlers would like to never see again - England gorged and feasted on runs until they dripped down their chins.
"Everything we tried didn't work and everything they tried came off. Normally that happens for an hour or two and you get a couple of wickets but it happened for as long as it did". In total, Morgan has scored 6187 runs, which also includes the runs that he scored for Ireland. In fact, the only time Australia looked like they could have pulled one game back was in the opener, where they eventually lost by three wickets.
Bairstow, who opened the batting and got the home team off to a flawless start as he and Jason Roy (82) put on 159 inside 20 overs, has now scored four centuries in his last six ODI innings. Seamer Andrew Tye finished on 0-100 off nine overs while the other two fast bowlers - Marcus Stoinis (0-85) and Billy Stanlake (0-74) - also went for plenty.
"I think this is definitely the best performance by a stretch".
The home batsmen were rarely troubled on a flat of a wicket as 21 sixes rained down on the ground where the Test side were bowled out for 60 on Australia's last visit three years prior.