It's two juggernauts going at it in Round 1 of March Metal Madness! Pantera and Mastodon are each titans in their own right, but one band's song here will be sent packing as the votes pile in to send either "Revolution Is My Name" or "Blood and Thunder" to Round 2 of the Mosh Pit Region in our tournament to determine the Best Metal Songs of the 21st Century.

Pantera carried the heavy metal banner throughout the '90s and released their final album, Reinventing the Steel, in 2000. The effort gave birth to some of the last Pantera classics, including the pit-inducing "Revolution Is My Name." The song saw the band delve into more midtempo grooves as Philip Anselmo employed a bit of a less aggressive vocal delivery, but the attitude had not altered a bit.

Going up against Pantera will never be easy, but Mastodon managed to step into the void the Texas band left and are one of the biggest acts to come out of the 21st century. Starting off with sludgy hardcore aesthetics, the quartet has evolved into one of the most unique entities out there. "Blood and Thunder" off Leviathan finds a balance between both facets of the band with a hardened lean but undeniably catchy songwriting starting to take shape.

So, which song will move on to the second round of March Metal Madness 2016? Listen to both tracks and vote for either Pantera's "Revolution Is My Name" or Mastodon's "Blood and Thunder" as the Best Metal Song of the 21st Century in the poll below!

(This poll will end on Tuesday, March 8 at 9AM ET. Fans are able to vote once per hour, so keep coming back to make sure your favorite song wins!)

Pantera, "Revolution Is My Name"

Mastodon, "Blood and Thunder"