Brazil's Alex Pereira roared back from a poor start to knock out Khalil Rountree Jr. and retain his light heavyweight title at UFC 307 on Saturday, while in the co-main event Juliana Pena beat Raquel Pennington to reclaim the women's bantamweight crown.

Pereira outlasts Rountree in a slugfest, while Peña becomes a two-time champ. Here's how it went down at UFC 307.

The main event of UFC 307 saw Khalil Rountree Jr. step into the cage against reigning UFC Light Heavyweight Champion Alex Pereira.

For more than a decade, Raquel Pennington carried a grudge against Julianna Peña dating back to their rivalry on UFC’s “The Ultimate Fighter” series. The veteran fighters clashed for the first time Saturday for Pennington’s women’s bantamweight belt at UFC 307 at the Delta Center.

Alex Pereira retained his light heavyweight championship in an intense, bloody battle at UFC 307, overcoming Khalil Rountree Jr. in a brutal main events