Ahhhh!!! Yeah!!! If you read those words with a Rob Halford scream and a James Hetfield grunt, then you're ready to vote in this legendary semifinal matchup of the Greatest Metal Frontman tournament!

In what was the closest match of any in this competition so far, Rob Halford edged out Rammstein's Till Lindemann with 50.05 percent of the votes in the quarterfinals. It was a back and forth battle, but the Metal God emerged victorious in the end. The legendary Judas Priest vocalist has also taken down Slayer's Tom Araya and Overkill's Bobby Blitz, but here he faces the frontman of perhaps metal's biggest band.

Metallica fans came through in masses for James Hetfield in the quarterfinals, giving him 60 percent of the votes against Pantera's Philip Anselmo. Hetfield has also knocked out Cannibal Corpse's Corpsegrinder and Anthrax's Joey Belladonna along the way, but here he most definitely faces his toughest challenge against the Metal God in this semifinal matchup!

Rob Halford or James Hetfield? Cast your vote for the Greatest Metal Frontman in the poll below! Voting for this round closes on Thursday, Nov. 21 at 9:00AM ET. Fans can vote once per hour, so keep coming back to make sure that your favorite metal musician wins!