UFC on ESPN: Ribas vs. Namajunas

UFC on ESPN: Ribas vs. Namajunas (also known as UFC on ESPN 53 and UFC Vegas 89) was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on March 23, 2024, at UFC Apex in Enterprise, Nevada, United States.

Background
A women's flyweight bout between Amanda Ribas and former two-time UFC Women's Strawweight Champion Rose Namajunas headlined the event.

A heavyweight bout between Chris Barnett and The Ultimate Fighter: Team Peña vs. Team Nunes heavyweight winner Mohammed Usman was scheduled for this event. However, Barnett withdrew due to unknown reason and was replaced by Mick Parkin.

Edmen Shahbazyan and Duško Todorović were expected to meet in a middleweight bout at the event. However, Todorović pulled out due to a serious knee injury and was replaced by A.J. Dobson.

A women's strawweight bout between Shauna Bannon and Stephanie Luciano was expected to take place at this event. However, Bannon pulled out for unknown reasons and was replaced by Julia Polastri. In turn, the bout was cancelled when Luciano was forced to withdraw due to falling ill with dengue fever.

A heavyweight bout between Junior Tafa and Karl Williams was expected to take place at the event. However, Tafa stepped in on short notice as a replacement for his brother Justin Tafa against Marcos Rogério de Lima at UFC 298 and was eventually unable to compete at this event after losing via TKO. He was eventually replaced by Justin at this event.

A featherweight bout between Billy Quarantillo and Gabriel Miranda was expected to take place at the event. However, Miranda was replaced by Youssef Zalal for unknown reasons.

A bantamweight bout between Cody Gibson and Davey Grant was expected to take place at the event. However, Grant withdrew due to injury and was replaced by former LFA Bantamweight Champion Miles Johns.

Bonus awards
The following fighters received $50,000 bonuses.
 * Fight of the Night: Jarno Errens vs. Steven Nguyen
 * Performance of the Night: Payton Talbott and Fernando Padilla

Aftermath
After the first ever disqualification due to biting took place at this event, UFC CEO Dana White gave a Bite of the Night $50,000 bonus to André Lima whose bout ended prematurely as a result of being bit on the arm by opponent Igor Severino. Severino was subsequently released from his contract with the promotion. The Nevada Athletic Commission also announced that it would withhold Severino's purse and he is expected to receive a heavy fine and lengthy suspension when the NAC holds its monthly meeting in April.