What was Michael Jackson's debut solo hit song (no Jackson 5 contributions)?

Got to Be There is the debut studio album by Michael Jackson, released by Motown on January 24, 1972. It includes the song of the same name, which was released on October 7, 1971, as Jackson's debut solo single. It sold nearly 900,000 copies in the United States and over 3.2 million copies worldwide.

Between 1972, when Michael's solo career began and 1975, Michael released four solo studio albums with Motown: Got to Be There (1972), Ben (1972), Music & Me (1973), and Forever, Michael (1975). Got to Be There and Ben, the title tracks from his first two solo albums, both became very successful singles. These songs are still being sold today.

Accordingly, when considering Michael Jackson, a statement in part by the Rolling Stones puts everything into perspective. It is: "No single artist – indeed, no movement or force – has eclipsed what Michael Jackson accomplished in the first years of his adult solo career...."