Holly Holm (right) knocked out Ronda Rousey with a kick to the head during their 2015 UFC title fight in Melbourne
American Holly Holm tamed the world's most feared female prizefighter Ronda Rousey with a stunning knockout victory for the Ultimate Fighting Championship (UFC) bantamweight title in Australia on Sunday.
Holm, 34, made a blistering start to the title fight before 56,000 fans at Melbourne's Etihad Stadium, becoming the first fighter to win a round against her fellow American, a former judo champion.
Rousey's past three fights had lasted just 64 seconds in total, but Holm delivered a head kick 59 seconds into the second round of the bout to send Rousey crashing to the canvas.
Holm, the underdog, clearly took points in the first round as her overhand lefts landed flush on Rousey's face.
She had Rousey staggering in the second round with some crunching left hooks, before finishing her off with a left-foot kick that landed flush under the champion's jaw.
It appeared Rousey was close to unconsciousness as she dropped.
Holm followed up with a few strikes before the referee stopped the fight, with Rousey looking considerably the worse for wear.
It was Rousey's first defeat in 13 bouts and left Holm unconquered in the mixed martial arts sport with a 10-0 record.
"I had so much love and support -- I thought how could I not do this," Holm said in the ring.
"There was lots of blood, sweat and tears, but it sure was worth it.
"I'm trying to take this in, but this is crazy."
Holm, who had claimed eight of her previous MMA victories by knockout and had gone the distance in her two UFC fights, said head kicks were the plan.
"I didn't want to kick her in the body and have her trap my leg... I went high and got it," she said.
She added: "Everything that we worked on presented itself in the fight.
"Every kind of grab that she tried to get... I have not spent this much time in the gym before any fight in my life... Everything we worked on happened tonight."
Rousey was unable to utilise her trademark armbar when she went for it two minutes into the fight.
The judoka took Holm to the canvas but she fought out of the predicament, quickly rising to her feet.
Rousey didn't speak to reporters after the fight and instead was taken to hospital suffering from concussion and a cut lip.
"She was transported because she got knocked out and her lip was split open," UFC president Dana White told reporters.
"She's completely bummed out and depressed, but that's it."
Rousey went into the bout with a series of dynamic knockout victories that earned her comparisons with Mike Tyson's rise in heavyweight boxing during the 1980s.
The pair had initially been due to fight in Las Vegas on January 2 but the contest was brought forward two months and moved to Australia in a bid to spread Rousey's appeal to another corner of the globe.