Prize Fight is a new PVP challenge type that requires gold to enter. Once in, you fight matched opponents in PVP matches. If you lose, you lose one of your three lives. If you win, you gain an extra Crate target selection when you run out of lives.
After three total losses, or seven total wins, the Prize Fight is over, and you can claim your prizes from the Crate that appears after the event. Playing again after this point requires another entry fee to be paid.