The 12-year-old singer from Swansea, Wales had previously performed the track to pass his first live audition on this year's series of Britain's Got Talent.
After he finished the song, Jafargholi said: "I love Michael Jackson. I just want to thank him so much for blessing me and every single individual on earth with his music."
Concert organiser Kenny Ortega then confirmed that Jackson had seen video footage of Jafargholi before he died and had wanted him to sing during the cancelled 'This Is It' residency at London's O2.
The song's writer Smokey Robinson told fans at the Staples Centre that he could not believe that a 10-year-old could sing with such soul and feeling when he first heard Jackson perform the track.