The night had been stacked against Superchunk’s success. Five bands preceded the Merge flagship to the Cat’s Cradle stage on Thursday, creating a rollercoaster of momentum that seemed to dip deep past the point of recovery before Superchunk could even play well after midnight. Parts of the venue’s PA and lighting rig lost electricity during a barreling bunch from the undeterred Rock*A*Teens, while Reigning Sound’s often-exquisite set slipped into a malaise of broken strings and out-of-tune guitars. “Dee-sastrous,” Greg Cartwright said, smiling between songs and sensing the late-night crowd’s waning energy and patience. “Seriously, we’re a pretty good band. Come check us out next time.”

But as much as Merge 25 could be any one band’s party, it is Superchunk’s; co-founded by the band’s frontman Mac McCaughan and bassist Laura Ballance, the label’s fourth release was also Superchunk’s first single. History at their backs, they emerged Thursday like three pinballs and a set of flippers, with McCaughan, Jim Wilbur and relatively new live bassist Jason Narducy careening in front of the emphatic motions of drummer Jon Wurster. They behaved not like a band that’s been playing for 25 years but instead like a just-formed crew of 25-year-olds, trying to impress the old cynics in the room with high-energy stunts and heavier, faster, hookier songs. Just three tunes in, for instance, Narducy bounced back toward the drum kit and fell down. He never let go of his bass and only realized he was bleeding from the face two songs later, when Wurster politely told him about the damage.

“The ol’ fake blood routine,” McCaughan explained.

For the next hour, Superchunk barreled through 15 songs, slashing from the old to the new and treating it all as equal parts of one emphatic whole. They sandwiched “What Do I,” that first single back in 1989, between the radiant 2012 sparkler “This Summer” and “FOH,” a highlight of last year’s I Hate Music. They showed veteran poise, as when the band kept playing “Low F” while a frustrated McCaughan swapped one dead guitar for another. He plugged in mid-verse, focused on the upcoming chorus and delivered.

But again, they really throve on youthful zeal, sneering at their age and the reality that it was a work night. Late into the set, for instance, they added an extemporaneous bridge to “Digging for Something,” McCaughan singing “I’m not that old/25 years old/Is really not that old” to the general shape of the melody. It was a tad hokey but entirely endearing, a recognition of circumstances and a rejoinder to them. McCaughan chided those standing in Cat’s Cradle’s notorious “Friendship Corner,” the area near the stage and the backstage entrance where old pals gather to watch bands before heading to Orange County Social Club. He asked them to sing along like kids, and they did.

Superchunk’s set was the exclamation mark—no, a series of them, emblazoned in italics—atop an uneven and long evening. Just after 7:30 p.m., Eleanor Friedberger began the night by herself, delivering her close-up reflections over tangles of dry guitar notes and brusque chords. Friedberger’s most fascinating songs link series of concrete images in an illusory fashion, so that she asks more questions even as she delivers new answers. There was a bravery, then, to that specificity when offered solo, as though Friedberger invited the early arrivers into some secret confessional. That only became more apparent when the four members of Telekinesis casually walked onto the stage, joining her for a final song. She dropped the guitar and grabbed the microphone, dancing about the stage as the ad hoc quintet swapped intimacy for bravado. The moment was tremendous, a reflection of the versatility that’s powered Friedberger’s already-prolific career. (Speaking of which, yes, she played one Fiery Furnaces song, “Benton Harbor Blues.”)

Telekinesis’ own set could have benefited from such an escalating curve; instead, Michael Benjamin Lerner and his three-piece started with “Coast of Carolina,” the appropriately ebullient second song from his Merge debut, and ended with “Tokyo,” the wonderful sing-along that follows it. Everything in between, though, stuck together, even when Lerner left the drumkit to step to the lip of the stage as an awkward, semi-dancing frontman. At one point, bassist Eric Elbogen yelled “Come on, y’all” and didn’t stop, as if he could sense that this set would need a lot extra if it were going to last through the weekend as more than a hazy memory.

The Clientele, who represented a mid-evening comedown in the midst of the six-band rock stack, seemed content to be just that. “Thanks to Merge for having us yet again,” offered frontman Alasdair MacLean after six songs, emphasizing that last part as though to apologize for The Clientele’s absence. They haven’t released a full-length in five years and have toured very little in the same period. Last night, though, their balmy, brooding tunes sparkled as well as they ever have, with MacLean’s guitar chiming like bells and twinkling like stars over a rhythm section that’s always balanced senses of torpor and tension.

With festivals like this, quiet bands tend to suffer loud crowds, and the back of the Cradle was indeed a madhouse of small talk. But close to the stage, people gathered in hushed reverence, giving the sadness and sentimentality of songs like “E.M.P.T.Y.” and “Reflections After Jane” the reflective space they politely demand. At one point, a woman in a red dress, standing just a few rows into the crowd, dropped a beer can to the concrete floor and gasped when it clinked, putting her hand over her mouth. No one seemed to mind, but that’s the vulnerability The Clientele’s music can create. It came as a welcome reprieve last night.

The technical troubles that plagued the somewhat rare sets from Reigning Sound and the reunited Rock*A*Teens stopped both bands short of full engagement, but moments of both woud-be-hit parades more than justified their length. Rock*A*Teens, for instance, seemed oblivious to the power loss and simply kept playing, meaning that their wonderful hooks-and-ladders pop simply had to fight through another barrier of distortion and intentionally abstruse mixing. The speakers returned during the middle of “Car and Driver,” the opening anthem of the newly reissued Sweet Bird of Youth. The crowd went wild, joining in the song like it had been a Top 40 smash in another time and place. Reigning Sound were brilliant when everything worked, with Dave Amels’ roaring organ lines (and maybe his hairstyle, too) wrapping around Cartwright’s songs like a warm blanket. They were like a set of radio waves reflected from another era, at least until the strings started to break.

But then there was Superchunk—spastic and practiced and, to be honest, perfect, the late-night wait made good.