Madonna kisses boxer beau Josh Popper at US ‘Celebration’ tour kickoff in Brooklyn

Strike a perch — there’s nothing to it.

While it’s been great to watch how much of Madonna’s “Celebration Tour” has lived up to its name — in honor of her 40th anniversary in music  — one of the most fun parts has been seeing which surprise guest will take the judge’s seat alongside the Queen of Pop during “Vogue.”

Since the tour opened in October at the O2 Arena in London, so far everyone from her oldest children Lourdes Leon and Rocco Ritchie to designers Donatella Versace and Jean Paul Gaultier to FKA Twigs and M’s longtime friend Debi Mazar has taken that seat of honor during the ballroom scene. 

And to kick off the US leg of her tour at Brooklyn’s Barclays Center on Wednesday night, Madonna could’ve certainly had her pick of celebs to bring it back to where it all began, in New York.

The diva returns to the BK arena on Thursday and Saturday before Madison Square Garden dates on Jan. 22-23 and Jan. 29.

But instead of going starry, she went sentimental with her boyfriend, boxing coach Josh Popper. After he began training Madonna’s 18-year-son, David Banda, at his Manhattan gym Breadwinners, the two have been romantically linked since early this year.

And their May-December romance — he’s 30, she’s 65 — was on sweet display at Barclays Center on Wednesday night. Although Popper was a little more reserved than some other judges as he basically received lap dances from both women and men with his girlfriend right beside, his big smile said it all as he embraced her big night — and her world.

And perhaps not so coincidentally, the hot highlight of the show is Madonna’s 1992 hit “Erotica” set in boxing rings, with dancers blurring the lines between pain and pleasure as mistress Dita — the singer’s dominatrix alter ego from that era — being clearly the one in charge.

There are more guests close to Madonna’s heart in the show: In addition to her 11-year-old daughter Estere fiercely working the runway during “Vogue,” there’s David Banda on guitar, in “Mother Father” and “La Isla Bonita”; daughter Mercy James, 17, on piano for “Bad Girl”; and Estere’s twin Stella hoofing it up to “Don’t Tell Me.”

“I’m the luckiest mother in the world,” said Madonna on Wednesday night.

“I get to perform every show with four of my six incredible, amazing children.”