Megadeth had a major music milestone yesterday. They took home the GRAMMY for best Metal performance for "Dystopia." 

However when the band went up to accept their award the GRAMMY house band played another band's music. That other band happened to be Metallica, of which Megadeth frontman and founder Dave Mustaine was a member of until they kicked him out. He was replaced by Kirk Hammett. 

The band played Metallica's "Master of Puppets." You could say it was a little awkward. 

Mustaine seemed to have a sense of humor about it because he began playing air guitar up the aisle to accept the award.