The long protest summed up a wild week for the race, with two horses eliminated before raceday even arrived, one by the selection committee and one by Racing Victoria vets.
But in the end it was a brilliant ride by John Allen that help his young Irish countryman Joseph O'Brien add the Cox Plate to the two Melbourne Cups he has already won.
State Of Rest was having his ninth career start and first in Australia and considering those disadvantages it is hard to argue the best horse didn't win, with wonderful New Zealand mare Verry Elleegant a strong third after coming wide.
Fellow New Zealand mare Probabeel never looked happy on the soft track once the pressure went on and it was a case of the rain almost coming too late for her. Had it come earlier and more plentifully it might have been easier to scratch her in what was a bordlerline decision.
Callsign Mav, having his last start for Hastings trainer John Bary, dropped out to second last.
Ironically a lack of rain in Sydney played against Probabeel's stablemate Entriviere in the Invitation, in which she finished fourth.
Not only did Randwick get upgraded to a good3, which was firmer than the Kiwi mare would have liked, but new rider Tommy Berry decided to work forward on Entriviere early and when he was unable to get in from three wide he pushed the button and ended up over-racing slightly outside the leader.
It was a case of nothing going right for the hot favourite all week (weather, draw, luck in the running) in the 1400m event won by Icebath, who stormed home from near last, Entriveire's usual racing pattern.
Earlier in the day, at The Valley former New Zealand-trained filly Drama Queen provided her new owners with a quick return with a brave win in stakes company.
The daughter of Super Easy, who only recently joined the Ben and JD Hayes stable in Victoria, won the Listed Crockett Stakes coming with a well-timed run under Luke Nolen.
The flashy chestnut defeated Our Heidi and New York Baby, putting her best foot forward after a plain effort when seventh at Mornington at her Australian debut.
Dream Queen advanced her career record to three wins from six starts, with a further two placings, but crucially enhanced her residual value with a stakes victory on one of Australia's premier days of racing.
Originally prepared by Ruakaka trainers Ken Rae and Krystal Williams-Tuhoro, Dream Queen had raced with success through the latter part of her two-year-old season and was sold after a strong win on her home track in July.
Dream Queen was originally bought by Rae on behalf of Northland owner Sue Martin off gavelhouse.com as a weanling for just $1500.
- additional reporting NZ Racing Desk