For a gruelling month, they have strutted their stuff in swimsuits, high heels and evening gowns, national costumes and Vietnamese au dai suits, trying to catch the eyes and win the hearts of jury panelists.
They have braved the tropical summer heat, a hectic travel schedule and endless rehearsals, local crowds and paparazzi, and even a bat that drew wide circles through the spotlight of one of the many preliminary events.
But the moment of truth -- when 79 dreams are crushed and one comes true -- was fast approaching in this 57th edition of a winner-takes-all contest that, organisers say, will be watched by a billion people in 170 countries.
The "Final Night" show starts at 8am Monday here to coincide with the prime-time Sunday evening TV slot in the United States, home of the extravaganza that is co-owned by millionaire-celebrity Donald Trump.
Speculation on the front-runner has run hot in the palm-fringed resort town of Nha Trang, fuelled by pageant-bloggers and scraps of gossip that have trickled out of the resort where the women are sequestered away.
Many favoured Miss Venezuela, 22-year-old Dayana Mendoza (height: 178cm/ 5 foot 10), whose country is admired here as a 'pageant powerhouse' that has long drilled contestants with makeovers, English classes and runway-practice.
"She seems to come with that mindset that, no matter what happens on the final night, you're only a Miss Universe contestant once in your life and you have to enjoy it," enthused one contest insider who asked not to be named.
"She has really endeared herself to the Vietnamese. She even tripped in the au dai section and she still won. She showed remarkable poise."
Miss Venezuela was also the hot favourite of punters on the betting website www.bookmaker.com, followed by other Western hemisphere beauties from Puerto Rico, Panama, the United States and Colombia.
The long-legged ranks of hopefuls were last week thinned out to 15 semi-finalists, although the shortlist has been kept a tightly-guarded secret, even from the contestants.
The select group of women with a shot at the diamond-studded gold crown will only be announced part-way through the show, before judges further slash their numbers in the swimsuit and evening gown sections.
The final interviews will be crunch-time in the event em-ceed by US talk show host Jerry Springer and Britain's ex-"Spice Girl" pop star Mel B, to determine who will succeed Japan's Riyo Mori as Miss Universe.
No matter who takes the 120,000-dollar crown -- and the cash, prizes, tiara, New York City luxury apartment and year of free world travel that go with it -- Vietnam already considers itself the real winner of the event.
Host town Nha Trang, located near the wartime US naval base of Cam Ranh Bay, has had a major facelift, including a new flower-lined airport road and a beachside concrete edifice that resembles a blossoming lotus.
The venue, the Diamond Bay resort -- where the women were protected by bodyguards, and eagle-eyed chaperones enforced a strict alcohol ban -- was built in less than a year, just in time for the event.
The limousines of Vietnam's new rich, who have paid up to 1,800 dollars for 'super-VIP' tickets, were parked on streets that police cleared weeks ago of street vendors and prostitutes in a customary big-event crackdown.
Vietnam lobbied hard last year to become the first communist nation to host a Miss Universe contest. Seemingly on a roll, it was also chosen last week as the location for the rival Miss World pageant in 2010.
Its leaders, eager to shine the global spotlight on Vietnam and boost tourism, have even turned a blind eye to the bikini section that, strictly speaking, breaches prudish laws banning risque exposure.