The 47-year-old singer joined Anthony onstage during his show at Radio City Music Hall to perform their Spanish-language song "No Me Ames."
"Always fun sharing the stage w this one... @marcanthony #NoMeAmes #radiocitymusichall #familia," Lopez captioned a picture of herself with the performer on Instagram
The "I Luh Ya Papi" singer later reunited with Anthony backstage to pose for a family photo with their two children, 8-year-old twins Emme and Max. Anthony's wife, Shannon De Lima, joined the foursome for the snapshot.
"#MiGente, thank you to the fans and @jlo for a wonderful concert. #AllAboutFamily backstage last night at @radiocitymusichall #ThePrivateCollection #Tour2016," Anthony wrote.
Lopez and Anthony split in 2011 after nearly seven years of marriage and finalized their divorce in 2014. Lopez called the split "the biggest disappointment of [her] life" in an interview with People and Entertainment Weekly in March.
"It was devastating and awful," she admitted. "I think both Marc and I thought at the time we would be together for the next 40 years until we die."
Lopez has since had an on-again, off-again relationship with Casper Smart but reportedly split from the dancer last week. She last released the album A.K.A. in 2014, while Anthony debuted 3.0 in 2013.