The Beach Boys took the stage at Riot Fest on Saturday, with actor John Stamos onstage with them.

Clad in black leather, Stamos joined founding Beach Boys member Mike Love, 60-year group veteran Bruce Johnston, and the touring band that now plays with them.

A published setlist indicated that The Beach Boys performed many of their 1960s classics — from the surf pop era of "Surfin' USA" to the "Pet Sounds" and "Good Vibrations" period a few years later — and of course, the 1988 hit "Kokomo."

Love and Johnston are the only classic-era members of The Beach Boys who are part of the present-day lineup. Brothers Brian, Carl, and Dennis Wilson have all died, and founding member Al Jardine no longer plays with the group.

Stamos first sat in with The Beach Boys on July 4, 1985, playing drums with the band at a concert at the Washington Monument, multiple published reports note. At the time, Stamos was a soap opera actor and a rising star.

The Beach Boys also appeared in a 1988 episode of the ABC sitcom "Full House" in which Stamos famously starred. Mike Love, Brian and Carl Wilson, Al Jardine, and Bruce Johnston appeared in the episode — Dennis Wilson had died five years earlier.

Riot Fest founder "Riot Mike" Petryshyn spent more than a decade trying to get the actor and musician to the festival, and finally succeeded.

It all started as a social media joke. Published reports pointed to a 2013 post on what was then known as Twitter that quipped, "I'm a little disappointed that John Stamos hasn't gotten back to us about the Jesse & The Rippers reunion show at Riot Fest."

Who are Jesse & The Rippers? They're a fictional rock band fronted by Stamos' Jesse Katsopolis character in "Full House" — known in particular for their covers of Beach Boys songs.

But of course, it was the actual Beach Boys with Love and Johnston, not Jesse & The Rippers, who ultimately played at Riot Fest. But getting Stamos to Riot Fest in some form had been an obsession for all the dozen years since that tweet was issued.

"We actually did a sculpture of John Stamos in butter," Petryshyn said this summer.

This also happened in 2013.

Last month, the actor made a list of demands "begrudgingly" to perform with the Beach Boys at Riot Fest this year.

Some of the demands included:

• Riot Mike, the founder of the festival, had to get a John Stamos tattoo.
• A John Stamos look-alike contest had to be hosted by Riot Fest.
• A local Chicago pizza restaurant had to create a Greek-style pizza named after and in honor of Stamos.

Petryshyn completed one of the demands by getting inked last month. The tattoo depicts an image of a stick of butter with the word "butter" in a faux-Greek font, and Stamos' name in a font that seems to resemble the font used for "Gyros" in Kronos gyros ad posters. Luckily, Stamos approved.

The John Stamos lookalike contest was indeed held Saturday, and Giordano's got the pizza requirement covered.

A butter statue of Stamos was also erected for Riot Fest this year — although published reports said unlike the one from 2013, this statue was not actually made of butter.

Among the others on the roster at Riot Fest on Saturday were Jack White, Buzzcocks, The Damned, All Time Low, Dropkick Murphys, Marky Ramone playing The Ramones, and Weezer.