Sheeran, 24, was in a music store at the mall when he heard the girl singing "Thinking Out Loud".
In a video filmed by his cousin, Murray Cummings, the musician quickly went out of the store and stunned the lucky young lady named Sydney Bourbeau as he jumped onto the stage.
Before the screaming crowd, he grabbed her microphone and assisted her to sing the track's second chorus, reported Aceshowbiz.
Bourbeau did not get to talk to Sheeran, but she may sing together again with him in the future. The singer's manager contacted the 13-year-old girl and offered her two tickets to an upcoming concert.
