Saying goodbye to a long-beloved rock band can be emotionally rough. Few farewell gigs, however, are also as physically unsparing as Slayer’s set Thursday night at the Armory in Minneapolis.

The Southern California quintet went out with the kind of intense, fiery impact it has shown throughout an impressively steady if never hugely commercial 37-year career.

This wasn’t a fade-into-the-sunset kind of thing. It was more Flight of Icarus blaze of glory.

In fact, Slayer’s 90-minute set was so striking, the performance itself seemed to answer the question why the band members decided to quit touring in their mid-50s: They clearly can still bring it, so why not quit while they’re ahead — and while the heads in the crowd are still banging away joyously?

This was a new one, though: A thrash-metal band calling it quits essentially for health and age reasons.

The genre’s godfather, Lemmy Kilmister of Motörhead, died before he could retire. Otherwise, the rest of Slayer’s peers are going relatively strong, including two of Thursday’s four opening bands, Anthrax and Testament, both dating back to the early-’80s just like the headliners.

Having such a stacked bill — also with the younger bands Lamb of God and Behemoth, each with Cookie Monster-echoing singers — only added to the endurance-status aspect of the nearly sold-out concert.

It was as if a challenge had been set: If the crowd was still rowdy till the end, then the band damn well better be, too.

A sizable amount of the 7,500 or so fans showed up early for Testament and stayed through Slayer’s visceral finale “Angel of Death.” God bless those Satan-saluting metal fans and their faithful dedication.

With the added excitement of getting to experience the newly reborn Armory — which suits metal shows like a fingerless leather glove, what with its massive, stone facade and booming but not echoey acoustics — the fans certainly delivered on their part.

From pale 18-year-olds to faded-tattoo-covered dads, they pushed toward the front of the stage in adrenaline-fueled fits of mayhem. Hundreds of them also bashed into each other in massive, convulsive mosh pits — not just during Slayer’s set, but all the rest, too.

The second opening band, Poland’s extreme-metal quartet Behemoth, brandished ghoulish makeup and some arty, Tool-like, rolling-thunder flourishes on top of its fearful, guttural sound. Virgina’s Lamb of God went over even better, with many fans shouting/growling along to such songs as “Walk With Me in Hell” and “Laid to Rest” while Chris Adler worked his dual kick drums like he was doing an extreme leg-muscle workout.

Anthrax was the act to beat, though. Even with Testament’s drummer Gene Hoglan filling in for Anthrax’s ailing Charlie Benante on short notice, the New York veterans literally didn’t miss a beat. Frontman Joey Belladonna hit notes that metal singers half his age would envy in “Indians” and “Madhouse,” while guitarist Scott Ian flawlessly led the crunch through “Antisocial.”

With brawny guitarist Kerry King as its anchor, Slayer took the stage to a bombastic “Repentless” and kept blasting away nonstop straight through to a manic, almost spazzy “Hate Worldwide” five songs later. Only then did singer/bassist Tom Araya stop to take a breath and scan the crowd with a long, contemplative glance.

“Thank you very much for showing up tonight,” he said, sounding like he was about to get emotional. Instead, he got cocky.

“You still have enough energy?” he prodded.

That was about it for the breathers and the sentiments. Slayer wham-bammed the crowd nonstop from there on out with songs covering an admirable range of eras.

Early-’80s staples such as “Chemical Warfare” and “Black Magic” — the latter of which had second guitarist Gary Holt playing his ESP guitar famously wood-stained with his own blood — sounded fuller and mightier than their simplistic origins. More recent fare such as the slow-building “When the Stillness Comes” and the blasphemous “Disciple” were just as thrilling.

Saved till the near-end, fan faves “Hell Awaits,” “Raining Blood” and “South of Heaven” were lit up by an arsenal of stage pyro that would’ve impressed the Armory’s original, militaristic operators. This show was as good an introduction to the venue as it was a summation of the headlining band.

Here’s Slayer’s set list from the Armory:

1. Repentless

2. Blood Red

3. Disciple

4. Mandatory Suicide

5. Hate Worldwide

6. War Ensemble

7. Jihad

8. When the Stillness Comes

9. Postmortem

10. Black Magic

11. Payback

12. Seasons in the Abyss

13. Dittohead

14. Dead Skin Mask

15. Hell Awaits

16. South of Heaven

17. Raining Blood

18. Chemical Warfare

19. Angel of Death