Thunderstorms and heavy rain did not dampen the spirits of racegoers who converged on Flemington, with an estimated 70,000 attending, up on a crowd of 10,000 at last year's Cup and from zero in 2020.
Temperatures dropped to 10C, the coldest Cup day in decades.
Sporting bold fascinators and ties and clutching umbrellas, punters gathered in brightly-coloured frocks and tailored suits to watch the race that stops the nation.
Supermodel Adut Akech and racing heiress Kate Waterhouse led the star arrivals inside the exclusive Birdcage enclosure.
Punter Marty Johnson said it was a relief to have some freedom after an extended lockdown during the COVID-19 pandemic.
"It's great to see everyone about and to engage with the world again," Mr Johnson said.
"This is an iconic event and probably one of the best days of the year so it feels awesome to be out and about again."
Mitch Ogden travelled from Queensland for the annual event.
"This is my first time in Melbourne, I've been here for about a week - I'm originally from Brisbane so it's great to see it down on the ground instead of on the screen for once and even with the weather, everyone is still out having a good time so I'm really happy to be here," Mr Ogden said.
Before dawn an unidentified person allegedly broke into the racecourse to protest the "toxic" racing industry, pouring an oil like substance on the track.
Victoria Police said it was investigating the incident, with climate change activist group Extinction Rebellion Victoria applauding the stunt as Racing Victoria scrambled to repair the damage.
"Melbourne Criminal Investigation Unit detectives are investigating after unknown offenders have broken into a racing facility in Flemington and poured an unknown substance over a portion of the track about 6am this morning," Victoria Police said in a statement.
There was almost as much action outside the Flemington gates as animal rights activists turned heads with bold signs calling for an end to the "archaic" sport.
The Coalition for the Protection of Racehorses urged people to say "Nup to the Cup", saying 139 racehorses died on Australian tracks in the past racing year.
This year's Melbourne Cup Carnival has partnered with local charity GIVIT to support flood-impacted people and communities throughout Australia.
28°C