Alt-J was a true “Fitzpleasure” at its Oct. 7 show at Bold Sphere Music at Champions Square. The band provided just the kind of hauntingly powerful performance fans expected, while opener San Fermin was a pleasant surprise.

San Fermin, an eight-piece ensemble from Brooklyn, New York, lent an indie-pop air that did a stellar job of livening up the audience in anticipation. Their onstage presence was confident and comfortable, even in the midst of more vulnerable numbers. They finished strong with the peppy title track from their latest album, “Jackrabbit.”

Alt-J appeared onstage in a flash of white light, kicking off with “Intro” from “This Is All Yours,” the album the band is currently touring. In a moment of calm before the storm, the crowd quietly observed the band’s almost eerie chanting, before being overcome in the sea of swaying that alternative music lovers have taken up in lieu of actual dancing.

The most appealing aspect of alt-J, perhaps, is how it manages to have such a powerful stage presence with such minimal embellishment. Just the silhouettes of four lanky British guys, their instruments of choice, and a meticulously planned light display were enough to drive the crowd with an energy that was palpable for the duration of the set.

The setlist was thoughtfully selected, balancing the best from both “An Awesome Wave,” their first album and “This Is All Yours.” Alt-J did not shy from playing their slower songs, like “Warm Foothills” and “Matilda,” which showcased the characteristic melodies of the band. Higher-intensity hits like “Fitzpleasure” and “Left Hand Free” pulled the crowd from the melodic daze and offered an opportunity for the audience to really let loose.

The show appeared to be on the short side, but a lengthy encore helped counter it. “Hunger of the Pine,” featuring vocals from Miley Cyrus, was easily one of the best performances of the night. No song, however, brought out the audience’s energy quite like the hit that propelled alt-J into the music scene, “Breezeblocks,” which they closed with.

Delivering a performance that put their album versions to shame, alt-J conquered Champions Square. It truly was a “Lovely Day.”