UFC bantamweight champion Amanda Nunes crushed the comeback hopes of Ronda Rousey by stopping her after just 48 seconds of the first round of their title fight at the T-Mobile Arena in Las Vegas on Friday.

Brazil's Nunes lit up the former champion from the off, rocking Rousey with a flurry of big punches, her superior boxing never allowing the Californian to close the gap and use her judo skills to take the fight to the floor.

Stunned early on, Rousey had no answer to the power of the 28-year-old and referee Herb Dean quickly stepped in to stop the fight as Rousey was stung again and could no longer defend herself. Rousey left the octagon immediately following the official decision, making no comment to the press.

The defeat could signal the end of the road for the 29-year-old Californian, who lost her title a little over a year ago when she was knocked out in stunning fashion by Holly Holm's head kick in the main event at UFC 193 in Melbourne.

Holm then lost to Miesha Tate in her first defense in March, and Tate did little better, turning over the belt to Nunes at UFC 200 in July.

Rousey, a judo bronze medalist at the 2008 Olympics, may be one of the biggest draws in the UFC, but she is not universally popular, and the fact that she was allowed to shun the media in the run-up to this fight was not well-received by fighters or fans.

But no-one can argue with her previous record as the first female bantamweight champion in the UFC and her six successful defenses of her title before succumbing to Holm. Her stature as one of the biggest draws in mixed martial arts saw her get a $3 million purse for Friday's fight, plus an undisclosed share of the pay-per-view revenues.

Nunes was critical of Rousey's trainer Edmond Tarverdyan. She says Taverdyan made Rousey believe she was a good boxer and put together a failed game plan that saw her coming out and box - as she did in the loss to Holm, who was a former world champion boxer with exceptional boxing ability.

"Yeah [I knew he would tell her to go toe to toe with me] because he thinks, she thinks she's a boxer you know. He's like putting this thing into her head and making the girl believe in that. I don't know why he did that. She has a great Judo, where she can go farther in this division, but he put some like crazy thing about his boxing and [her career started to] go down, and they tried to win [with] that. I'm the real striker here, and [after I won I went over and told him that because] this is the only thing I want to look at him like and say," Nunes said.

"That's it for her. For sure she's going to retire. She can't take anymore. If she wants a rematch I'm going to do the same thing, because she can't take my punches."