Winger Miller starred in a brilliant first-half performance from Australia's rugby women at the Salford Community Stadium in Manchester on Saturday, wrapping up her treble in just over half-an-hour as the slick 'Roos blitzed seven tries in just 33 minutes.
But the Samoans, faced with conceding a three-figure score, regrouped courageously, starved the Aussies of possession until another late burst of excellence saw the 'Roos plough over for three late scores.
The scoreline topped the Wallaroos' previous biggest World Cup win, a 62-0 trouncing of South Africa back in 2010.
There were try doubles for fullback Caitlyn Halse, the youngest ever World Cup Wallaroo at the age 18, and forward replacement Adiana Talakai, while Katalina Amosa, Emily Chancellor, Eva Karpani and player-of-the-match Cecilia Smith also went over for tries.
Sammy Wood kicked six of eight conversions, while replacement Lori Cramer slotted over three others.
The huge victory had been expected against the weakest team in a power-packed Pool A, headed by hosts and tournament favourites England, who'd set out their stall on Friday in the tournament opener with a 69-7 demolition of USA.
But the way the Australians held the Samoans scoreless with doughty defence while also putting together some fluid attacking bodes well for their key encounter against the US next weekend in York, which will likely determine who goes through to the quarter-finals with England.
The one-sided pattern was set within 90 seconds as hooker Amosa went over from a rolling maul, with Miller then being freed on the left wing five minutes later for her 10th international score.
Halse marked her World Cup bow with a barnstorming individual score through the centre, before co-captain Chancellor burrowed over to make it four within a quarter-of-an-hour.
When prop Karpani blasted over, things just got worse for the visitors with Ana Mamea binned for one offside too many, before Miller struck twice in quick succession, the second while supporting terrific work on the right flank from fellow winger Maya Stewart.
The biggest cheers of the day came when the underdogs encamped briefly on the Australia line just before the break before the biggest boos greeted the TMO's intervention, ruling they'd been guilty of a dangerous clean-out.
At 45-0 down at the break, the only question seemed to be not whether the Australians would barrel past their record World Cup points tally - they scored 68 points while conceding 12 win against South Africa in 2006 - but whether they might even tally 100 points.
But the proud Samoans made a nonsense of such predictions, dominating possession early in the second half until outstanding centre Smith, one of 11 Samoan siblings who's now proud to be playing in the green-and-gold, ploughed over to bring up the half-century.
Tiring rapidly, the dominant Australian forwards cashed in with Talakai ploughing over twice in 10 minutes after coming off the bench, before Halse completed her landmark day in the 77th minute by finishing off a clinical attack.
Miller had a more concerning end to her big day when she got smacked head-to-head in a reckless challenge by Melina Grace Salale, who received a game-ending 20-minute red card, but the Australian did not look too groggy.
