Which fighter defeated Ronda Rousey at UFC 207?

Amanda Nunes defeated Ronda Rousey at UFC 207.

The women’s bantamweight title fight headlined UFC 207 on December 30, 2016, in Las Vegas. Nunes overwhelmed Rousey with fast boxing and ended the contest by first-round technical knockout after 48 seconds. The win confirmed Nunes as the champion and extended her reign over the division.

Rousey had been away from competition for more than a year after losing the title to Holly Holm. Her fight with Nunes was her return bout, but it was also the final professional MMA appearance of her career.

This question is distinct from UFC 193, where Holm defeated Rousey. Nunes’s victory came later, at UFC 207, and used a different finishing method. Nunes subsequently became one of the most accomplished champions in women’s UFC history.