What was the first UFC event to feature a women's fight?

UFC 157 was the first UFC event to feature a women’s fight. Held on February 23, 2013, at the Honda Center in Anaheim, California, it was headlined by Ronda Rousey defending the women’s bantamweight championship against Liz Carmouche.

The bout marked the UFC’s formal arrival of women’s MMA after years in which the promotion had not included female fighters. Rousey had been the Strikeforce women’s bantamweight champion when the UFC absorbed that division, and she was recognized as the UFC’s inaugural women’s bantamweight champion before the event.

Carmouche created danger late in the first round by attacking Rousey’s back and attempting a neck crank. Rousey escaped, regained position, and finished the fight with her trademark armbar at 4:49 of round one. UFC 157 therefore combined a historic first with a successful title defense.