Lady Gaga celebrates end of tour partying with her fiance Michael Polansky on the LES

Lady Gaga managed to recapture the magic of Rivington St. in the 2000s after her Madison Square Garden show on Monday night.

After her final performance for her “Mayhem” tour, the “Abracadabra” singer and her fiance Michael Polansky head downtown to Maison Nur for a celebration with family and friends.

One person described it as Gaga’s “return to the Lower East Side.”

She famously honed her performance skills in the Manhattan neighborhood 20 some years ago, singing at now defunct dive bar St. Jerome’s with acts like Lady Starlight, jazz man Brian Newman and Breedlove, who were both on hand this week to fete her accomplishments.

Only this time, she had Polansky, who is also her artistic collaborator, by her side.

“Their vibe is just really good. His influence on everything is really affable. He’s not just some man hanging out or walking behind her. He’s her partner in the truest sense,” a source said of the couple.

The duo looked over their guests, including Maggie Gyllenhaal and Dylan Mulvaney, from the club’s upper level balcony and appeared to be equal hosts. He held court with guests at his table, while she entertained her closest childhood friends and her mom, Cynthia Germanotta at another table.

Gaga’s pals gushed over how proud they are of her, with one saying, “this show was literally the most fun I’ve seen her have on stage.”

Ultimately, the evening was “bittersweet.” “It’s sad for the era to come to an end, and to walk into a party that signifies the end, but now [Gaga] can say, ‘I did it. It’s in the can, history was made,’” the first source said.

Meanwhile, Maison Nur neighbor and Baked by Melissa co-founder, Benzi, entertained the cigarette smokers along with his dog. We’re told he even had a few people pop in for a private tour of his Time To Be Happy gallery, next door.