BYERS, Colo. — Just when it seemed like the 2013 summer concert season was over, Riot Fest Denver invaded the tiny farm town of Byers Saturday with the decidedly non-idyllic likes of The Replacements, Iggy Pop and The Stooges and AFI.

Also billed as a carnival and sideshow, Riot Fest features attractions such as wrestling, midway games and self-styled “freaks.” But the biggest thrills one the first night of the two-day festival came from a slate of revitalized artists.

That list included not just the obvious names — Iggy Pop was as sinuously creepy at 66 as ever, and the senior citizens of Guided by Voices put on an admirable rock clinic — but also several resurgent, younger acts.

California goth-punk group AFI nearly started a literal riot after frontman Davey Havok dove into the crowd. And New York emo band Brand New put on a powerful set that seemed designed to shatter internet rumors that the group has been having problems.

Riot Fest continues Sunday.