Miley Cyrus Performs Despite Illness

Miley Cyrus shook off undisclosed health problems to perform at a birthday party for boxing legend Muhammad Ali Saturday night.

Cyrus was joined by her boyfriend Liam Hamsworth for Celebrity Fight Night in Arizona, which doubled as Ali's 70th birthday party.

The singer tweeted, "Stoked for @CelebFightNight :) awesome to have [singer] @JohnzoWest and Liam at my table here tonight."