Normally one of the NBA's most buttoned-up coaches, Erik Spoelstra let his guard down and showed a completely different side during a performance at Shane Battier's annual charity karaoke event, "Battioke."

Spoelstra, 44, was accompanied by his girlfriend, former Miami Heat dancer Nikki Sapp, on stage for a rendition of Michael Jackson's "Billie Jean." Spoelstra puts in a good effort and even shows off some snazzy moves, but he doesn't have the best command of the lyrics.

Luckily for the man who led the Heat to the past four NBA Finals, his girlfriend is there to help him along.

Afterwards, Sapp had this to say about the couple's act:

It's performances like these that make "Battioke" so special. In its fourth year, Battioke has blossomed into a night full of players, coaches and executives cutting loose and having fun. Here's Spoelstra's mentor, Pat Riley, singing "Twist and Shout":

Michael Beasley and Henry Walker went in a different direction with Vanessa Carlton's "A Thousand Miles."

Proceeds from the event go toward Shane and Heidi Battier's Take Charge Foundation, which works with underserved youths in Miami, Houston and Detroit.

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