Ronda Rousey has dominated her sport like no other professional athlete in the last few years, and the UFC champion looks to add to her impressive resume when she returns to the octagon on Saturday night. Rousey will face veteran fighter Holly Holm at UFC 193 with her women’s bantamweight title on the line.

In 12 career fights, no opponent has come close to beating Rousey. The 28-year-old has a perfect record since her first professional mixed martial arts fight in 2011, winning each time by knockout. Only one of Rousey’s fights has gone beyond the first round, and the champ is seemingly getting better each time she competes.

Rousey last fought on Aug. 1, knocking out Bethe Correia in just 34 seconds. Rousey has made especially quick work of her last three opponents, needing just 66 total seconds to win her last three fights. It would be considered a monumental upset if Rousey can’t improve her career record to 13-0 on Saturday, but her upcoming opponent presents a new set of challenges that she’s never faced in the UFC.

Holm, 34, is undefeated in her career, as well, going 9-0. She had her first MMA fight 21 days before Rousey made her professional debut, making the transition from being a world-class boxer. Holm went 33-2-3 as a boxer, winning several titles and becoming one of the most feared women in the sport.

Rousey knows it won’t be easy to make quick work of Holm.

“This one’s going to be a much longer fight because [Holm’s] a 19-time world boxing champion with 100 percent takedown defense and head-kick knockouts,” Rousey said on “The Tonight Show Starring Jimmy Fallon” last month. “She’s undefeated and an amazing athlete, and definitely the biggest threat to me, especially on paper and stylistically.”

Holm last fought on July 15, beating Marion Reneau in a unanimous decision. While the win helped keep Holm perfect in MMA, she hasn’t exactly been dominant in the UFC. Both of Holm’s fights since signing with the UFC last year went the distance, including a split decision over Raquel Pennington in her first fight with the company.

It was a surprise to many that Holm was given the chance to face UFC’s top star. Miesha Tate, who has won her last four fights and lasted into the third round against Rousey two years ago, looked poised to get another chance to beat the champ. But despite being relatively new to the sport, Holm is getting her shot and believes she can avoid mistakes that some of Rousey’s past opponents have made.

"I don't want to go into the fight thinking, 'She's going to come out with this, so I'm going to throw this,'" Holm said, via Yahoo Sports. “A fight is unpredictable. That's why people love to watch fights. You don't know what's going to happen. So, I want to go in with kind of an open-ended plan and be able to adjust along the way."

Rousey and Holm will headline the pay-per-view at Etihad Stadium in Melbourne, Australia, where the UFC attendance record of 55,724 might be broken. When Rousey headlined UFC 190 two months ago, the PPV event nearly reached one million buys.