It's the semifinals of our Rocktober Rumble tournament with four songs left competing for the title of best hard rock hit of the 21st Century. Who's left? Check out our next semifinal matchup.

Three Days Grace have emerged from their region with the single "Animal I Have Become." The hard rocking cut just edged out Shinedown's "Second Chance," following victories over Seether's "Rise Above This" and Breaking Benjamin's "The Diary of Jane" in the first two rounds. "Animal I Have Become" was the lead single off the band's highly successful One-X album and spent seven weeks on top back in 2006. Reacquaint yourself with the song below.

Avenged Sevenfold fought their way through the heaviest bracket with a hard fought victory over Tool's "Schism" to get to the final four. That came on the heels of wins over Slipknot's "Duality" and System of a Down's "Chop Suey" in the early Rocktober Rumble rounds. "Nightmare" climbed all the way to No. 2 back in 2010, serving as the title track from their album of the same name. Revisit the hit song in the player provided.

So will it be Three Days Grace's "Animal I Have Become" or Avenged Sevenfold's "Nightmare" advancing to the Rocktober Rumble finals? That's up to you. You can vote once per hour through the deadline of Friday, Oct. 28 at 10AM ET.

Three Days Grace, "Animal I Have Become"

Avenged Sevenfold, "Nightmare"

Loudwire
Loudwire
Loudwire
Loudwire