The documentary focuses on Michael Jordan’s final year with the Chicago Bulls during the 1997-98 NBA season.
Its first two hours, which aired on Sunday, were watched by an average of 6.1 million viewers on ESPN and ESPN2.
Most people stayed around for the second episode, which had 5.8 million views, and in total there were 3.5 million viewers in the key age bracket of adults aged 18-49.
This is equivalent to a 2.7 rating, which far outperforms any other Sunday night television.
ESPN first started producing originals in 2004, and its last longform documentary was OJ: Made in America in 2016.