5 of the biggest upsets in UFC history

4. Holly Holm def. Ronda Rousey - UFC 193

Eight years before Strickland's win, and 100 UFC pay-per-view events before it, another historic upset took place in Australia.

Entering the UFC from Strikeforce at the end of 2012, Ronda Rousey kicked open the door for women in the UFC. In fact, she was awarded the first-ever UFC women's bantamweight championship.

Beginning with her win over Liz Carmouche in the first women's fight in UFC history at UFC 157, Rousey — who previously won bronze in judo at the 2008 Olympics — tallied six successful defenses of the bantamweight title before coming face-to-face with Holly Holm at UFC 193.

Rousey entered the fight at 12-0 and noticeably did not mince words on her opinion of Holm. But Holm, a highly successful boxing champion, had Rousey's number on this night.

Holm put a pounding on Rousey before delivering a brutal head kick that knocked her out, putting Rousey's reign as the top woman in the UFC to an end.

Holm would lose the belt in her first defense against Miesha Tate about four months later at UFC 196, but she would be involved in the bantamweight and featherweight title pictures over the coming years.

But for Rousey, this upset defeat was the beginning of a bigger downfall. Rousey came back for just one more fight, losing to Amanda Nunes at UFC 207, before retiring from MMA. Rousey would be inducted into the UFC Hall of Fame in 2018 — becoming its first female inductee. She joined the WWE that same year, having since gone on to become a three-time women's champion, a one-time women's tag team champion and winning the 2022 Women's Royal Rumble.