Booker dropped 59 points in the Suns' 125-92 loss to the Jazz, becoming the first player in NBA history with 50 points in a game in which his team lost by 30 or more, according to ESPN Stats & Info.
The 6-foot-6 guard also became the third player in league history to reach 50 points in a single contest in which no teammate reached double figures, joining David Robinson and Kobe Bryant. Suns rookie center Deandre Ayton was the team's second-leading scorer with nine points.
Booker's previous season high was 55 points in a triple-overtime loss against the Washington Wizards in December. He scored the fourth-most points in an NBA game this season, trailing only Houston Rockets star James Harden (61, twice) and Charlotte Hornets point guard Kemba Walker (59).
Booker played 41 minutes and shot 19-of-34 from the field while knocking down five 3-pointers despite facing numerous double-teams by the Jazz. He also converted 16-of-17 free throws.
The Suns, who are competing for a high draft pick in the Zion Williamson sweepstakes, sit in last place in the Western Conference with a 17-58 record. Phoenix plays the Wizards on Wednesday night.