UFC Fight Night: Waterson vs. Hill (also known as UFC Fight Night 177, UFC on ESPN+ 35 and UFC Vegas 10) was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on September 12, 2020 at the UFC Apex facility in Enterprise, Nevada, part of the Las Vegas Metropolitan Area, United States. Background A light heavyweight bout between former UFC Light Heavyweight Championship challengers Thiago Santos and Glover Teixeira was originally scheduled to serve as the event headliner. However, it was announced on September 3 that Teixeira tested positive for COVID-19 and the bout was rescheduled for October 3 at UFC on ESPN: Holm vs. Aldana. A women's strawweight bout between former Invicta FC Atomweight Champion Michelle Waterson and former Invicta FC Strawweight Champion Angela Hill was initially scheduled to take place three weeks earlier at UFC on ESPN: Munhoz vs. Edgar. However, due to undisclosed personal reasons for Waterson, the bout was moved to this event. Subsequently, the pairing was announced as the new main event after the postponement of Santos/Teixeira. This was the first time in UFC history that a bout involving an African-American woman served as the event headliner. A lightweight bout between Roosevelt Roberts and Matt Frevola was previously scheduled to take place at another event earlier in the year. However, that event was cancelled in mid-March due to the COVID-19 pandemic. The pairing was rescheduled for this event. In turn, Frevola pulled out of the fight on September 11 citing an injury and was replaced by Kevin Croom. A light heavyweight bout between Ed Herman and Gerald Meerschaert was previously scheduled for August 1 at UFC Fight Night: Brunson vs. Shahbazyan. However, on the day of the event it was announced that the bout had been scrapped from the card after Meerschaert tested positive for COVID-19. The pairing was left intact and was rescheduled for this event. In turn, Meerschaert once again pulled out of the bout and was replaced by John Allan. Allan already had a bout booked against Roman Dolidze on November 21 at UFC 255, but was expected to compete in both of them. Herman then suffered another opponent change on September 3, as Allan pulled out due to visa issues and was replaced by Mike Rodríguez. A lightweight bout between Khama Worthy and Ottman Azaitar was previously scheduled to take place earlier this year at UFC