What happened: Johnny Walker and Waldo Cortes-Acosta are set to headline UFC Vegas 124 following a late adjustment to the card. Both fighters stepped in on short notice to keep the heavyweight headliner intact for the Las Vegas event.

Why it matters: The sudden main event booking provides immediate divisional stakes after late reshuffling threatened the marquee slot. A decisive finish positions the winner for higher-profile heavyweight matchups as the promotion sets its upcoming calendar.

What to watch: The heavyweight main event streams Saturday at 8 p.m. ET.