Paul Westerberg was propped up by Billie Joe Armstrong in more ways than one Sunday night in Louisville, Ky., where the Replacements played the Forecastle Festival. / Jeff Wheeler, Star Tribune

It seems like the more shows the revamped 2013-2014 lineup of the Replacements play, the better they get at doing what the old Replacements were best at: messing around. Fortunately, Sunday night’s performance at the Forecastle Festival in downtown Louisville, Ky. – the first in a string of three summer gigs leading up to the St. Paul show on Sept. 13 -- never got too messy, and ultimately proved this version of the Replacements is even better at playing it straight. Despite whatever Paul Westerberg has to say.

“We’re the Cements, the world’s greatest Replacements tribute band,” he announced at the start of the 75-minute set, where they played to about half of the festival’s 25,000 attendees sandwiched between Jenny Lewis and Beck on the big stage (I’m guessing there wasn’t a lot of inner-band camaraderie for them backstage).

For the fourth time in the seven Replacements shows since last August, Green Day frontman Billie Joe Armstrong once again joined in as a third guitarist, this time playing the entire set and blending in without messing up the formula – although, he did mess up. The band’s only multi-platinum musician came in at the wrong time during “Nowhere Is My Home,” much to Westerberg’s and bassist Tommy Stinson’s amusement. “Our one-day rehearsal did not pay off,” Westerberg cracked.

Armstrong made up for it by fixing one of the boss’ botches. Westerberg’s microphone slipped down its stand at the start of “Can’t Hardly Wait,” which Paul kept singing crouched over like a baseball catcher until the rookie came over and propped it back up – and then kissed the singer full on the lips.

That wasn’t the only time Westerberg sang at knee level, either. He delivered the first half of “White and Lazy” laid out on the stage after his harmonica fell. Later, he played half of “Merry Go Round” without his guitar, the head of which he inexplicably smashed hard onto the stage (and irreparably broke) – much to Stinson’s and Armstrong’s amusement.

“Billie’s gonna take that home and sell it on eBay later,” Stinson quipped.

Aside from the unplanned tomfoolery, there were two other big surprises in Sunday’s set: “Message to the Boys” was played for the first time, a mid-‘80s outtake finished on a 2006 anthology. The 'Mats nerds loved hearing it, but it hardly proved a highlight. Even bigger, Westerberg actually broke from character and let out a brag at one point in the show. After he and the crowd sang an especially lovely version of “Androgynous” together, he said, “It’s a good song, I must admit.”

Coincidentally or not, “Androgynous” was right about the time the show really turned into a seriously exhilarating rock ‘n’ roll affair alongside many of the best/best-known Replacements songs -- the ones that would take a whole lot more shenanigans than these to muck up. After a trouble-free “I Will Dare,” they tore through an especially ripping mash-up of “Love You Till Friday” and Chuck Berry’s “Maybellene,” soon followed by spirited, blaring versions of “Left of the Dial,” “Alex Chilton,” “Can’t Hardly Wait” and “Bastards of Young.”

After poking fun at how they dealt with the lack of a proper set list – “I tell [Tommy] what we’re playing and he tells everyone else one by one” – Westerberg let fly a candid zinger that would’ve raised the eyebrows of any booking agents in the crowd. “Hey buddy, can you spare a quarter of a million dollars?” he asked, probably not making up that figure.

Westerberg and Stinson will be paid even more off the instantly sold-out Sept. 13 Midway Stadium show -- and they stand to more than double the profits should they add a second show (any concert industry professional would tell them they should). Here’s hoping they earn their bread as well there as they did once again Sunday.

The Forecastle set list:

Takin’ a Ride  / I'm in Trouble / Favorite Thing / I'll Be You / Nowhere Is My Home / Color Me Impressed / White and Lazy / Achin' to Be / Kiss Me on the Bus / Valentine / Tommy Gets His Tonsils Out / Androgynous  / I Will Dare / Message to the Boys / Love You Till Friday (with Maybellene) / Merry Go Round / Left of the Dial / Alex Chilton / Can't Hardly Wait / Bastards of Young  ENCORE: I Don't Know (with Buck Hill)

The 'Mats weren't the only Minnesotans playing to a big crowd in Louisville on Sunday. Trampled by Turtles also drew a good chunk of the attendees and a very good response for their late-afternoon set on the fest's second-largest stage, finishing up a quick East Coast run that also included a back-rubbingly good Letterman performance. Highlights included the rousing opener "Repetition" and the quieter, evocative tunes "Hollow" and "Winners," all from their album that came out Tuesday, "Wild Animals." Mandolinist Erik Berry earned a nice serenade from the crowd after frontman Dave Simonett announced it was his birthday. Even nicer was hearing the out-of-town fans sing along to "Alone" and "Wait So Long" just as verbosely as they do back home.

After being the consummate replacement sideman and fixing Paul Westerberg's collapsed mic stand, Billy Joe Armstrong planted a kiss on The Replacements leader Sunday evening. / Jeff Wheeler, Star Tribune