After surviving an early scare from spirited challenger Liz Carmouche, Rousey (7-0) latched in her signature technique – the armbar – to score a first-round submission win in the first defence of the title she was granted this past November.
Despite the massive expectations that were placed on her shoulders entering the contest, Rousey said she felt comfortable throughout the entire experience and looks forward to returning to action in the near future.
"I was actually less nervous walking out than I was for some of my earlier fights," Rousey said. "I felt like the UFC champion, and I know how hard I am working. This was a wild ride, and I can't wait to get back in the octagon."
The bout served as the main event of "UFC 157: Rousey vs. Carmouche," which took place at Honda Center and drew 15,525 fans for a US$1.4 million live gate, according to UFC officials.
Rousey, a massive favourite in the UFC's first women's bout, found herself in early trouble as Carmouche grappled her way to the back position and began to look for a rear-naked choke.
The hold looked tight for several moments, but Carmouche couldn't quite get her arm under the neck, and Rousey eventually shook her off and freed herself from danger.
"I had the choke across her mouth and couldn't get it to her neck," Carmouche said. "I actually have her teeth marks all over my arm."
From there the champion took over, using her world-class grappling skills to lock in an armbar attempt that spelled the beginning of the end.
Carmouche (7-3) fought as time ticked off the clock, but she eventually lost control of the defence and was forced to tap out with just 11 seconds in the opening round.
"That was the most vulnerable a position I've been in so far in my career," Rousey said after the win. "That was pretty tight, that neck crank, and I was very happy to get out of it. She had the choke across my mouth and the angle pushed my mouthguard out of my mouth."
Rousey has now submitted all seven of her professional opponents via first-round armbar, a judo move that has dislocated at least two prior opponents' elbows.
Meanwhile, Carmouche received a warm ovation in defeat and now takes her spot alongside Rousey in the UFC history books. However, the former U.S. Marine said it will not be the crowning achievement in her MMA career.
"This isn't the highlight of my career," Carmouche said. "So far, maybe. But the highlight is going to be when I win some fights in the UFC and come back for the title."
In the night's co-headliner, former UFC champion Lyoto Machida (19-3) earned a contentious split-decision win over MMA legend Dan Henderson (29-9). The three-round fight failed to impress as the two were reluctant to engage for much of the fight.
"He's a very great opponent for me, and I have a lot of respect for him," Machida said while fans booed. "My strategy was to keep the fight standup, and I think I got it. I think I completely dominated the first round, second round, third round."
Despite earning a slow-paced victory that left fans booing at the bout's conclusion, UFC president Dana White said Machida is expected to challenge for the promotion's light-heavyweight title against the winner of an April bout between current champ Jon Jones and challenger Chael Sonnen.
Earlier, bantamweight Urijah Faber beat Ivan Menjivar with an acrobatic rear naked choke late in the first round, Robbie Lawler stopped Josh Koscheck with 1:03 left in the first round with a series of strikes, and Court McGee beat Josh Neer by unanimous decision in his welterweight debut.
— With files from The Associated Press.