This quarterfinal matchup of the Greatest Metal Drummer tournament features two highly respected former members of two of metal's favorite bands, as ex-Slayer drummer Dave Lombardo takes on ex-Dream Theater stickman Mike Portnoy!

While Dave Lombardo is no longer in Slayer (as of earlier this year), there's no denying his legendary standing in the metal world. His skills behind the kit are highly respected, as evidenced by his thrashing of his first two opponents -- Municipal Waste's Dave Witte in Round 1 and Morbid Angel's Pete Sandoval in Round 2. But now comes Lombardo's stiffest competition!

Mike Portnoy is a virtuoso of drumming, with 25 years in Dream Theater, followed by stints in Avenged Sevenfold, Adrenaline Mob and currently the Winery Dogs. In Round 1, Portnoy took down Sean Reinert of Cynic and Death. He then followed that up with a victory over the Atomic Clock, Gene Hoglan of Testament. But he'll have his hands full against Lombardo in this round.

Dave Lombardo or Mike Portnoy? Cast your vote for the Greatest Metal Drummer in the poll below! Voting for this round closes on Sunday, Sept. 8 at 11:59PM ET. Fans can vote once per hour, so keep coming back to make sure that your favorite metal musician wins!