Together again!

Jennifer Lopez and Marc Anthony reunited in New York City on Aug. 27 -- but it was for one night only.

Just days after splitting from dancer-choreographer Casper Smart, 29, J.Lo surprised her ex-husband's Radio City Music Hall audience when she joined Marc on stage for a duet during his "Private Collection" concert.

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She not only sang "No Me Ames" with Marc, 47, in Spanish, but embraced him when the song came to an end.

"Always fun sharing the stage w this one... @marcanthony #NoMeAmes#radiocitymusichall #familia," Jennifer captioned a photo of herself singing with Marc on Instagram later that night.

Always fun sharing the stage w this one... @marcanthony #NoMeAmes #radiocitymusichall #familia

A photo posted by Jennifer Lopez (@jlo) on

J.Lo, 47, looked incredible in a sheer, skin-baring black gown with a plunging neckline and a high slit as she emerged from a set of stairs and joined Marc on stage amid deafening cheers in a moment captured on video by fans.

Afterward, Marc shared a photo of himself, J.Lo and their 8-year-old twins Max and Emme posing backstage alongside his new wife, Shannon de Lima, 28, as well as with his side of the family.

"#MiGente, thank you to the fans and @jlo for a wonderful concert. #AllAboutFamily backstage last night at@radiocitymusichall #ThePrivateCollection #Tour2016," Marc captioned the photos.

Jennifer's appearance comes two weeks after Marc showed up in Las Vegas for her "All I Have" show at the Planet Hollywood Resort & Casino.

J.Lo gave her ex a shout-out during her Vegas performance show, telling the crowd, "You're an international legend and icon, but you're also my baby daddy" as Marc -- who later posed backstage with Jennifer and her then-boyfriend Casper shortly before the split -- stood up and took a bow.

Marc and Jennifer announced their own breakup in 2011 after seven years of marriage.

Their divorce was finalized in 2014, the same year Marc married Shannon, a Venezuelan model and beauty pageant veteran.