This Round 2 matchup in the Greatest Metal Bassist tournament pits pure metal power against progressive mastery.

Pantera / Down / Kill Devil Hill bassist Rex Brown has provided the low end for some of metal's most groove-based masterpieces. Brown experienced massive success with Pantera, establishing a signature tone along with late guitar legend 'Dimebag' Darrell Abbott. The bassist moved on to play for yet another successful band, Down, with singer Phil Anselmo. Now with Kill Devil Hill, Brown continues to perform as one of metal's most valuable players.

Martin Mendez, along with masterful frontman Mikael Akerfeldt, is a key piece of the iconic Opeth. The Swedish progressive metal band has gone through tons of style changes, integrating more dynamics than perhaps any heavy act in history throughout the band's 10 studio albums. Mendez has appeared on eight of those albums, weaving seamlessly between each sharp turn.

Rex Brown or Martin Mendez? Cast your vote for the Greatest Metal Bassist in the poll below! Voting for this round closes on Sunday, Oct. 6 at 11:59PM ET. Fans can vote once per hour, so keep coming back to make sure that your favorite metal musician wins!