In the Boss Fight Event, five players battle one player's "Boss" Brawler. The Boss has very high health, improved damage output, and enhanced abilities, but their ability to self-heal is greatly reduced. The Boss attempts to stay alive for as long as possible while the others try to defeat the Boss as quickly as possible. The time on the clock when the Boss is defeated determines how many Coins the participants receive. The Boss "wins" the mode by surviving past 2 minutes and 15 seconds, for which they receive the most coins. Likewise, the normal players win by defeating the Boss in under 2 minutes and 15 seconds. The game will automatically end if the Boss is still alive after 8 minutes. This is an unranked mode, so Trophies cannot be earned or lost.
- Darryl and Bull: These Brawlers can use their Supers to escape from large groups of Brawlers.
- Spike: This Brawler's Super is amazing against the Boss since it slows them down significantly, allowing the group to get many hits on the Boss.
- Bosses can get more coins the longer they stay alive. Instead of fighting, you can simply run away from enemies to last longer.
- Attack the Boss from all sides in order to overwhelm them.