Black balloons emblazoned with white skulls were launched into the crowd midway through Hammerlord’s headlining appearance Saturday at the Beaumont Club. Many of the props were immediately destroyed in the violent mosh pit near the stage. Almost all of the roughly 1,200 heavy metal fans who attended the third edition of Hammerween managed to escape the event unscathed. Eight heavy metal bands performed in the seven-hour exhibition of frightful music.

Hammerlord, a Lawrence-based thrash act, warranted its status as the event’s headliner. While the quintet’s bassist, Terry Taylor, is the organizer of Hammerween, the technical proficiency and captivating showmanship the band displayed in its hourlong set made it the standout act of the miniature metal festival. Besides Hammerlord’s remarkably precise playing on searing material like “Tombstone Piledriver,” vocalist Stevie Cruz provided witty comic relief. Dressed as the cartoon figure Skeletor, Cruz never broke character.

Costumes played an integral role at Hammerween. About half the audience — Cruz referred to attendees as “beastly boys” and “ghastly girls” — was dressed for the occasion. Devils, zombies and French maids abounded. Musicians also wore seasonal attire. Tennessee Murder Club, Hammerween’s second-best act, didn’t even need to change its usual wardrobe. The South Dakota-based band wore its customary ghoulish masks on stage as it performed brutal material like “Flesh Mob.”

Horror-movie-style masks are also a staple of the Independence-based band Troglodyte. While not quite as impressive as Tennessee Murder Club, its grim perspective and infernal brand of death metal inspired Hammerween’s fiercest clashes in the mosh pit. At the Left Hand of God commanded the most committed audience. The locally based band’s utilitarian thrash was the clear crowd favorite.

Provocative race-oriented statements made by vocalist and drummer Cameron Walker provided the most interesting moments of a brief set by Enemies Laid To Rest, a biracial local band. Kansas City’s In the Shadow sounded like a compact version of the popular metal band Slipknot. David Hasselhoff on Acid, another local collective, added avant-garde elements, including ironic bursts of jazz to its brand of metal. High Rise Robots opened the show.

While the evening’s music hit with the force of a sledgehammer, the party-minded audience was uniformly cheerful. The Beaumont Club — often derided as a claustrophobic venue — was remarkably hospitable Saturday. Both the outdoor space on the north side of the Westport establishment and the auxiliary bar on its south side were accessible to Hammerween patrons. Interesting horror-related vendors and first-rate sound quality added to the Beaumont’s appeal.

The content of much of the music presented Saturday was acrid and grotesque. Yet the chaotic noise led to liberating catharsis for much of the audience, making Hammerween a truly happy Halloween celebration.