March Metal Madness has seen some fierce competition to determine the Best Metal Song of the 21st Century. Either System of a Down's "Chop Suey!" or Avenged Sevenfold's "Nightmare" will advance to the Semifinals as representatives of the Devil Horn Region!

System of a Down got off to a good start in Round 1, steamrolling Behemoth and coasting their way to Round 2. "Chop Suey!" dominated once again, overtaking Godsmack's "Awake" with nearly 55 percent of the votes. The dynamic and spastic song will need a huge showing here in the Quarterfinals to triumph over Avenged Sevenfold's "Nightmare"

Avenged Sevenfold and "Nightmare" crushed Children of Bodom's "Everytime I Die" in the first round. Keeping the momentum rolling, the song picked up over 62 percent of the votes against Lamb of God's "Laid to Rest" with sights set on taking out System of a Down's "Chop Suey!" next.

So which song will move on to the Semifinals of March Metal Madness 2016? Listen to both tracks and vote for either System of a Down's "Chop Suey!" or Avenged Sevenfold's "Nightmare" as the Best Metal Song of the 21st Century in the poll below!

(This poll will end on Tuesday, March 22, at 9AM ET. Fans are able to vote once per hour, so keep coming back to make sure your favorite song wins!)

System of a Down, "Chop Suey!"

Avenged Sevenfold, "Nightmare"