Halfway through Slayer’s set last Saturday at the Centrum in Worcester, singer Tom Araya stopped to thank the legendary metal band’s legions of devoted fans. “Just like the song says, Slayer is eternal,” he proclaimed in his patented play-scary voice. “It’s the flame that burns in your fucking heart!” He’s got a lot to be thankful for: both Slayer and the night’s headliners, Pantera, hit their commercial peak in the early ’90s, but right now they’re doing a decent job of filling arenas together as proof of their staying power. And though they invited new-metal upstarts Static-X and Skrape along for the so-called Extreme Steel tour, last weekend’s show was all about the old school.

Pantera are on their third trek around the country in support of last year’s Reinventing the Steel (Elektra), which yielded the scorching rock-radio hit “Revolution Is My Name.” The opening “Hell Bound” started the concert off with big-budget flair: the huge Pantera logo hanging above the band erupted in flames during the first chorus, with extra fire shooting up from the steel-encased speaker cabinets on either side of the stage. The mosh pit generated its share of heat as well, even if the crowd was a bit more grizzled than that at your average contemporary metal show.

The beginning of Pantera’s hour-and-a-half set was mostly for the diehards, as were singer Phil Anselmo’s frequent redneck tirades. The band picked up steam as they headed into the homestretch, stripping their machine-gun assault down to the essentials for the straight-up hardcore nuggets “Strength Beyond Strength” and “Fucking Hostile.” The high-strung power ballad “This Love” got the most violent response from the crowd, but then a series of prolonged encores took their toll. By the time Pantera closed with the definitive “Cowboys from Hell” and “Walk,” both the band and their fans were too drained to do these justice.

Slayer, on the other hand, were still getting warmed up when their 45 minutes came to an abrupt end with the bludgeoning “Angel of Death.” Every metal fan knows what to expect from a Slayer show by now, but the band’s rattling blur of noise hasn’t dulled with age. Opening with “Raining Blood,” they crammed in as many standards as they could, including the morbid sing-along “Dead Skin Mask” and an abbreviated “Seasons in the Abyss.” And the pair of tunes they played from their forthcoming disc, God Hates Us All (American), showed that they, like Pantera, have no intention of letting up — or going soft — any time soon.