Metallica kicked off their brief European tour in the Czech Republic on Monday (May 7) by performing their groundbreaking 1991 self-titled disc (aka The Black Album) in its entirety for the first time ever. Not only did they rock the whole album, they played it backwards -- now that's metal!

Months after celebrating their 30th anniversary, Metallica is honoring the 20th anniversary (a year late) of their most commercially successful album. We all knew they planned on jamming the tracks from The Black Album during their current overseas tour and at one night of the upcoming Orion Music + More festival, but nobody expected their first ever live run through the album to be in reverse order.

"What a great show here in Prague to start off the 20th Anniversary of the Black Album!" a post on Metallica's website reported on the Czech Republic gig. "The band surprised everyone, and played it backwards! During and after Sandman, it was pyro, pyro, pyro, and pyro!!! Sandman had fireworks, Fuel had the big flames..."

After opening the set with Metallica classics like 'Hit the Lights,' 'Master of Puppets' and 'For Whom the Bell Tolls,' the thrash metal kingpins broke into the last track on The Black Album -- 'The Struggle Within" -- after a video intro set the early 90's mood. From there the band fired through the tracklist in reverse order, closing the set with the explosive 'Enter Sandman.' They then book-ended the set by performing the non-Black Album tracks 'Fuel,' 'One' and 'Seek & Destroy' for the encore.

Metallica have 10 more European dates prior to the maiden voyage of their two day festival, Orion Music + More, which takes place June 23-24 in Atlantic City, New Jersey. They are also in talks with Rick Rubin to produce their tenth studio album at some point this year.

Watch Metallica's 'Black Album' Intro Video + 'The Struggle Within'