The best and worst from Day 2 of the Minnesota Yacht Club Festival — plus highlights for Day 3

The music got louder, the fans turned sweatier, and the main stage was a lot more fiery as the Minnesota Yacht Club Festival moored its second 10-hour day Saturday.

Headliners Fall Out Boy brought an arsenal of pyro to the main Skipper Stage to top off Day Two at the second annual music fest at St. Paul’s Harriet Island Regional Park. There might have been greater danger of the 35,000 attendees getting burned by the Chicago pop-punk band’s explosives and flame-throwing devices than from the seemingly minor lightning threat that cut short Friday’s closing set by Hozier.

Weather-wise, Saturday’s festival was a little humid but otherwise picture-perfect, with partly cloudy skies, high-70s temps and (nodding to Sunday’s main stage players Blind Melon) no rain. Festgoers kicked back on blankets or just their heinies across Harriet Island’s grassy areas, contentedly soaking up the partial sun and the full-volume music.

Among the artists, there was a remarkable “no sweat” mantra even in the most heated hours of the day. In their midafternoon set on the Crow’s Nest second stage, emo-rock vets Motion City Soundtrack impressively pulled off the daunting challenge of performing without ailing singer Justin Pierre. They called up a few friends to stand in for Pierre, including Fall Out Boy vocalist Patrick Stump — whose own band also had to perform without one of its co-founding members and didn’t miss a beat.

Here’s how things fell in Fall Out Boy’s set and the rest of Saturday’s festival.

Motion City’s lemonade-out-of-lemons turnaround really was the giddiest and most memorable of Saturday’s many fun performances. Stump came out at both the start and end and sang eight songs total, including “My Favorite Accident” and “Everything Is Alright,” with minimal help from a lyric sheet. A trio of Twin Cities scene makers were sandwiched between Stump’s stint on vocals, including Nadi McGill and Kathy Callahan of Gully Boys as well as indie-pop craftswoman Ber.

“Anybody else ever have to follow Patrick Stump to the stage?” Ber cutely quipped.

That baton-passing marathon set wasn’t the only one by a homegrown favorite to feature guest singers. Guitar star Cory Wong’s sophisticated instrumental funk with jazzy flourishes felt like a cool, fresh breeze in the sunny humidity even without vocals. A dedicated collaborator, Wong brought Remi Wolf to the microphone to take everyone higher with a spirited rendition of Chaka Khan’s “Tell Me Something Good.”

Wolf’s own set was definitely something good. The ultra-high-energy California funk-pop singer came off like a cross between a bawdy comedian, a Richard Simmons-like exercise/dance instructor and a wild punk-rock frontwoman. She showed off roof-rattling vocal power, too, in hits like “Hello Hello Hello” and “Sexy Villain” and an alluringly sensual delivery in her cover of Fleetwood Mac’s “Dreams.”

The mood got a lot more serious with Jake Clemons, best known as the saxophonist with Bruce Springsteen and the E Street Band. Like his Boss, Clemons was not shy about speaking his mind about what’s happening in the world: “We should be people filled with love and compassion,” he concluded before delivering the blistering “We, the People,” followed by barking the bracing “Stop the Wars.”

Ohio frat-rockers O.A.R. came off like a benign party band with a flair for a faux island sound, and they offered an overlong treatment of Led Zeppelin’s “Fool in the Rain” that ironically felt too yacht-rocky for the Yacht Club.

As for Fall Out Boy, the band was firing on all cylinders even without guitarist Joe Trohman in tow — especially early in their set with the visceral hits “Sugar, We’re Going Down” and “Thnks fr th Mmrs.” However, the set dragged as it moved onto more recent tunes, and the overall momentum and fun spirit of Saturday’s lineup seemed to slip.

Weezer’s greatest-hits style performance on the Skipper Stage before Fall Out Boy actually felt more like the headliner set of the day, with more of the audience singing and head-bobbing along to the familiar radio hits such as “Beverly Hills” and the finale “Buddy Holly.”

After mixing in more modern hitmakers and recent buzz acts during its first two days this year, the Yacht Club will lean into its bread-and-butter booking scheme on Sunday with a schedule loaded with Gen-X nostalgia. It’s not just the angsty grrr-rock the ‘90s are best-known for, though.

Antagonistic punk headliners Green Day and electro-grunge vets Garbage will fit that bill, but the lineup also features a trio of happier, sillier, groovier hippie-spirited radio darlings oft overlooked from that era: Sublime, 311 and Blind Melon. The latter band was added late to the bill after local favorites Semisonic had to bow out for medical reasons. Sublime is coming to town for the first time with Jakob Nowell out front, son of the “What I Got” hitmakers’ late bandleader Bradley Nowell.

The festival kicks off again at 12:50 p.m. with local opener Landon Conrath, touring newcomers Winona Fighter and Grace Bowers & the Hodge Podge, and then a couple of similarly named and kindredly feminist rock buzzmakers, the Beaches and Beach Bunny. Only a limited number of the pricier VIP-tier tickets are available for Sunday on the festival’s website, minnesotayachtclubfestival.com. General admission tickets are sold out.