Amanda Nunes retained her bantamweight title by knocking out Ronda Rousey in the first round of the main event at UFC 207 at T-Mobile Arena Las Vegas on Friday night.

Nunes moved in and delivered right-handed blows to Rousey’s head before the referee called the fight. The fight lasted 48 seconds, which is the third-fastest in UFC women's bantamweight history. Rousey needed just 16 seconds to defeat Alexis Davis at UFC 175 and 34 seconds to beat Bethe Correia at UFC 190.

Nunes landed 27 of 47 strikes while Rousey was seven-for-14.

“I knew I was going to beat the s--- out of Rousey like that,” she said after the fight.

Nunes's victory is her seventh and breaks a tie with Rousey for most wins in UFC women’s bantamweight history.

Watch the end of the fight below:

Rousey made her return to the ring for the first time since losing to Holly Holm in November 2015 and surrendering the women's bantamweight title. Rousey was knocked out in the second round with a head kick.

•Ronda Rousey's Return: A look back at her career timeline

After taking her first career loss, Rousey went into seclusion from the public eye. She focused on her entertainment career, making an appearance on Ellen and hosting Saturday Night Live.

PHOTOS: AMANDA NUNES DEFEATS RONDA ROUSEY

Before Friday night's win by Nunes, no woman had successfully defended the bantamweight title since Rousey lost. Holm lost to Miesha Tate in March, and Tate lost to Nunes at UFC 200 in July. Holm is competing in the featherweight division now, and Tate has announced her retirement.

Rousey largely declined to promote Friday night’s fight, and went on a media blackout in the days before the main event. She did not do promotional appearances. In her Ellen appearance, Rousey also noted that she is heading into the final fights of her career.

Before pay-per-view totals, Rousey is expected to take home $3 million for the fight while Nunes earns about $200,000.

Nunes reportedly approached Rousey after the fight and said, “You did a lot for the sport.”