Madonna got emotional on stage Friday night ... breaking down before dedicating a song to her son.
Madge was in Auckland, New Zealand and spoke to the crowd about Rocco. She told fans, "there's no love stronger than a mother for her son" before losing it.
Madonna went on to dedicate "La Vie en Rose" to the 15-year-old.
As TMZ reported ... Rocco has been living with his dad Guy Ritchie in London during a nasty custody battle between Guy and Madonna. A judge ruled the two figure out an amicable resolution to visitation but has not forced Rocco to return to his mom.