It’s one of the cardinal rules of heavy metal: always respect your elders.

By Bryan Rolli

Young bands should heed this advice, as they consider the war the heavy metal pioneers of yesteryear had to wage against a conservative audience just to break their genre into the mainstream. Had those bands not stood their ground, releasing one landmark album after another and tirelessly traveling the globe, then it’s possible a tour like last night’s — featuring Power Trip, Deafheaven, Anthrax and headliners Lamb of God at the Moody Theater — would never exist in the first place.

Practically speaking, these newcomers also need to give credit where credit is due, lest they forget a group of elder statesman like Anthrax is still perfectly capable of blowing them out of the water — which is exactly what they did.

Following a cathartic performance from black metal/shoegaze hybrid Deafheaven, the New York thrashers came out swinging with “Fight ‘Em ‘Til You Can’t,” off their 2011 comeback album, “Worship Music.” Singer Joey Belladonna sprinted across the stage wielding his signature half-microphone stand, a smile breaking out across his perfectly tanned face as he pointed to an audience member smoking a joint in the balcony.

If scientists ever get serious about halting the effects of aging, they ought to study Belladonna’s body as a reference. The 55-year-old singer still sports his immaculate black mane, and probably fits into the same jeans as he did in 1987 — a welcome change from the myriad of middle-aged singers who have filled out substantially since their heyday (here’s looking at you, Vince Neil). More importantly, he hit every ear-piercingly high note with ease, his gorgeous vibrato perfectly intact.

The rest of the band raged behind Belladonna, maintaining the breakneck pace and ballistic energy. Lead guitarist Jonathan Donais fired off solos left and right as rhythm guitarist Scott Ian played a flurry of power chords while kicking his feet up and whirling around the stage. With legs stretched impossibly far and bass slung low across his body, Frank Bello kept up with both guitarists while also locking into an unbreakable groove with drummer Charlie Benante.

During their final song, “Indians,” Ian stopped the band just as they began the circle pit-inducing breakdown. “Charlie surmises that not all of you are having as much fun as you should be having,” he said to the crowd, egging them on. “It’s a fucking metal show! This is the war dance!” They launched into the breakdown again. This time, everybody war danced.

By the time Anthrax cleared the stage to make way for the headliners, it seemed like the crowd couldn’t possibly get any more hysterical. (Spoiler alert: they did.)

Two video screens on either side of the stage played footage of buildings tumbling to the ground before Lamb of God ripped into “Desolation,” off 2012’s “Resolution.” Lead singer Randy Blythe leapt from the riser at the front of the stage, whipping his dreadlocks back and forth and signaling for the audience to scream along with him. Although his Nike running sneakers might not have been the most stereotypically “heavy metal” attire, they were the perfect choice for the frontman, who refused to stop moving for the duration of the band’s 75-minute set, racing across the stage even as he made way for guitarists Willie Adler and Mark Morton to solo.

Whereas Anthrax thrives on dizzying speed, Lamb of God is all about stomp and swagger.  Adler and Morton traded off groovy riffs and wah-drenched solos as drummer Chris Adler switched between lightning-fast double bass and pummeling breakdowns on a dime, suggesting the band owes an equal debt to both Pantera and Slayer.

For all the blinding heaviness they brought to the stage, Lamb of God sounded best when they mixed melody and muscle. “My hands are painted red, my future’s painted black,” Blythe sang on “512,” a cut off the band’s newest album, “VII: Sturm Und Drang,” inspired by the time he spent in a Czech prison during a manslaughter case. (He was acquitted in 2013.)

Fans got a chance to catch their breath during “Overlord,” a six-and-a-half-minute quasi-ballad on which Blythe alternates between a sinister croon and bloodcurdling scream. The song built steadily until the halfway mark, then drastically shifted to a full-on thrash metal anthem that invoked the biggest circle pit of the night.

The band played several more fan favorites before retreating backstage, only to come roaring back with an encore that included their two most popular songs, “Laid to Rest” and “Redneck.” Look past all the vitriol and you might’ve felt that maybe, just maybe, the quintet was having a little fun onstage. But it was only a fleeting glimpse, and just like that, they were back to business.

In the end, Anthrax clinched the victory by a hair at the Moody Theater. They packed the perfect one-two punch of blinding virtuosity and youthful exuberance, and their 50-minute set flew by in the blink of an eye. Not that the audience was keeping score: on the contrary, they were thrilled to be at one of the few metal shows where every band gives a knockout performance.

With odds like that, you just can’t lose.