When celebrity ring announcer Michael Buffer declared New Kids on the Block “the heavyweight champions of the boy band world” in an introductory video Friday night at the Smoothie King Center, the claim overreached.

New Kids on the Block today are actually New Men on the Block, with all the members in their 40s. They have aged out of the genre and often made their manliness a theme Friday, appearing in various stages of undress.

On occasion, they walked an awkward line between boyhood and manhood, such as when Joey McIntyre and Jordan Knight appeared shirtless and chest-hairless despite their ages, but the overwhelmingly female crowd clearly had loved the group since the ’80s and didn’t stop during this show.

New Kids on the Block formed in 1985, split in 1994 and first reunited in 2008. Friday night, the members’ performances suggested differing attitudes toward the group.

McIntyre approached the night like a true believer, fully committed to the dance moves and the spirit of the group in its late 1980s heyday. His vocals often approached an off-Broadway theatricality, and because of that, his performance during the group’s first hit single, 1988’s “Please Don’t Go Girl,” was a showstopper.

Donnie Wahlberg has an acting career now, including a regular role on the CBS series “Blue Bloods,” so he seemed to approach the night with nothing to lose. As a result, he often appeared to be having more fun than anyone else on stage. He’s not the bad boy anymore, but there was nothing precious about his performance either. He engaged the audience at every chance, sometimes to detriment of precision.

Danny Wood appeared to be there as a favor to the others. He took his time whenever the New Kids trekked from one end to the other of the stage that stretched the length of the Pelicans’ court in the middle of the Smoothie King Center. During a sequence in which the band sang around musical director Rob Lewis’ piano, Wood stayed seated while the others moved around.

Still, when everybody was game and in motion, the show was good fun. The members didn’t have the seemingly carefree energy they had almost 30 years ago, but they were never less than professional and seemed to be enjoying themselves.

They understood the gig was to take what they did seriously but not too seriously, and they laughed with one another over a silly step during “My Favorite Girl.” They were attentive to their limited choreography when center stage, where a series of rising pedestals lifted the guys to differing heights.

A run of solo spots by Knight, McIntyre and Wahlberg late in the show demonstrated that the New Kids need one another. Each revealed musical weaknesses that explained their marginal careers as solo artists — not that the women in the audience cared. Throughout the night, nothing could go wrong enough to diminish the energy and enthusiasm of the crowd.

Opening act Nelly sang/rapped “Hot in Herre,” “Country Grammar” and his part in Florida-Georgia Line’s “Cruise” over such muddy tracks that nothing was clearly audible, but that didn’t slow the crowd. The night’s other act, TLC, missed the late Lisa “Left Eye” Lopez badly and lacked energy except when her raps were piped into the songs, but the crowd squealed with delight for much of the set anyway.

Because of that, the enthusiasm often seemed to really be for the women in the crowd themselves and the roles these songs and artists played as they grew up, as both harbingers of maturity and talismans of youth.

When they squealed at the sight of Knight’s bare torso, it was less of an “I want that” than an “I saw that” moment. When Wahlberg brought out New Orleans’ Big Freedia and her dancers for a bounce interlude, the audience loved that too.

It’s easy to quibble about the show. It was too long and used up much of its best material in the first 20 minutes, and you could wonder how five men in their 40s don’t have a gray hair among them.

But the crowd seemed to connect with the performers as much through memory and imagination as the reality of the show, and the reality fed that beautifully.

One Direction has this to look forward to.