Winx also overtook Makybe Diva as Australia's highest stakes earner ($15.6 million) when she held off Humidor in a closer-than-expected finish at Moonee Valley.
The daughter of Irish stallion Street Cry didn't have things her own way, however, having to fight off Humidor's determined challenge in the straight under her regular rider Hugh Bowman.
"She's made history. I was born the year Kingston Town won his first Cox Plate and she has emulated the great".
In beating former New Zealander Humidor by a long neck, the six-year-old became only the second horse to win three Cox Plates since its inception in 1922.
".She will be recognized as one of the greatest horses to grace the Australian turf, and to be part of her career, I can't explain how much that means". You don't worry about the weather because it makes no difference to her.
"She's unbeaten for nearly three years now and I'd be lying if I said I didn't go to bed at night thinking of her record".
Trainer Chris Waller is letting the dust settle following Winx's record-equalling third straight Cox Plate victory before announcing what lies ahead for his superstar mare.
"She's an awesome athlete, and firstly, that helps her race so well, and secondly, it helps her recover so quickly as well". We will just look at her and see how she has recovered.
Winx has won the Cox Plate for a third consecutive time.
Who Shot Thebarman settled second last of the seven runners in the Cup (2500m) and came home strongly to beat Libran by a half head with the same margin to Cismonte. "We would love to have her".
Bowman is the country's leading Group One jockey, and Waller is Australia's leading Group One trainer.
Earlier in the day the mare appeared relaxed and calm as she was brought to her stall to prepare for the run.
Waller had said that there was "a bit of confidence" going into the race, with Winx rated a $1.15 chance to defeat the other eight in the field.