MMA sensation Ronda Rousey (9-0) defended her bantamweight title with a first round TKO win over Sara McMann (7-1) at UFC 170 in the Mandalay Bay Events Center in Las Vegas, Nev., on Saturday night. Unlike her previous eight wins, which all came by way of armbar, this victory was gained with a perfectly executed knee to the liver.

McMann started the fight on a high note and brought the action to Rousey, landing a few shots on the champion early on. Rousey absorbed the punches and took McMann into a clinch against the cage. There, she delivered a swift knee to McMann’s liver, dropping her to the canvas where she was left defenseless. Rousey started to rain blows on the challenger and referee Herb Dean decided to step in and stop the fight with 66 seconds gone in the first round. The stoppage was the fastest ever recorded so far in the short history of women’s UFC.

“We studied her videos and noticed that no one ever really tries to hit her to the body,” Rousey told Joe Rogan in the Octagon immediately after the fight. “Since she’s a wrestler, she has that bent posture, so we felt like it was the best thing to concentrate on the liver shot for this camp. The left knee has been working for me the most during this camp, and I thought if I stayed consistent on that one spot that it would eventually work.”

Rousey was roundly booed after the fight, but it was not her fault that the fight was stopped. While some may argue that the challenger was in the process of getting up, Dean was faced with the scenario of a fighter on the floor unable to defend herself with another fighter about to tee off on her head.

Rousey now turns to her second career in Hollywood, and she will start shooting her role in Entourage in a few weeks. Check out the videos.

Fight Highlights:

McMann Post-Fight Reaction:

Check out this photo from Rousey’s Instagram of the knee that caused all the damage: