Rousey, then women's bantamweight champion, was undefeated in 12 career fights and, arguably, the biggest name in the UFC at the time. Holm, a former world champion boxer, was unbeaten in 10 mixed martial arts fights, six of which had come by knockout.
The match up promised fireworks for the fans at Marvel Stadium (then Etihad) – and delivered. The fight was the main event on a card loaded with international stars, with nine local fighters mostly spread through the preliminary bouts. Four years on, it remains the most-attended event in UFC history.
All going to plan, that record will be broken today when Kiwi Israel Adesanya meets Auckland-born Australian Robert Whittaker for the UFC's middleweight championship at the same venue. While top international talent had to be brought over in 2015, local fighters will be front and centre this time around. In the four confirmed bouts on the main card, five of the eight fighters are from either Australia or New Zealand, with a total of 12 athletes from Australasia fighting during the event.
In the past, putting faith in local talent to sell out a 57,000-plus seat arena would have been absurd. Now, there's a good reason UFC boss Dana White can do just that.
"I wanted this fight in Melbourne. This is where I wanted this fight to happen," White told the Herald.
"I knew that what I really needed were two local guys that were perceived as some of the best in the world and, obviously, if you can get somebody from there that's a world champion it's a no-brainer. I've got both – I've got a guy from Sydney, Australia, fighting a guy from Auckland, New Zealand. You couldn't write a better script than that.
"Australia is a massive, massive market for us right now. As the fan base continues to grow, the talent continues to grow. I'll tell you what, after we do this event this sport is going to explode in Australia – much bigger and much crazier than it is now. This fight is going to be a massive game-changer for the sport, the athletes and the fans in Australia and New Zealand."
In the past 18 months, mixed martial arts has catapulted into the national spotlight in New Zealand, led in large part by the rapid rise of Auckland's City Kickboxing gym. Of the six Kiwis currently signed with the UFC, five fight out of the gym while Hamiltonian Luke Jumeau, who fights out of core MMA, is a regular visitor for sparring.
On Sunday, Adesanya, Jumeau, Dan Hooker and Brad Riddell will all take to the octagon as part of UFC 243, while fellow City Kickboxing UFC stars Kai Kara-France and Shane Young will be in Melbourne to take in the action. Adesanya, Hooker and Kara-France are all ranked inside the top 15 fighters in their respective divisions, while the contingent of active Kiwis fighters on the roster holds a combined 21-6 record in the UFC.
"It's come tremendously far from where it was even a couple of years ago," City Kickboxing coach Eugene Bareman said of the growth of the sport in New Zealand.
"I still think it's got a little way to go yet before it gets the recognition I think it deserves, but I'm happy with where it is at the moment and all of our success, if it can in some way bring a bit more light to the sport and especially help increase the numbers and the involvement with people in the sport in New Zealand then I'm very happy to have a small part to do with that."
With more than 50,000 people in attendance at Marvel Stadium today, and millions watching live around the world in what is one of the most anticipated cards this year, the trajectory the sport is on shows no signs of slowing down.
Hooker, the longest tenured Kiwi UFC fighter having made his debut in 2014, will meet No6 ranked lightweight Al Iaquinta in the co-main event on the card in what promises to be a fan-friendly fight.
The 29-year-old Kiwi has been on a tear since moving up to lightweight in 2017, with a 5-1 record, and said with UFC 243 being a stadium show, it sent a clear message as to just how much appreciation there was for the sport in Australasia.
"This is mainstream, man. This is going to be on the mainstream news back home in New Zealand. The growth has been incredible."