Mitchell's impressive performance included 13 rebounds and nine assists as Cleveland achieved a historic milestone by winning their 13th consecutive game to start the season. The last team to accomplish such a feat was the 2015-16 Golden State Warriors, who set the record with 24 straight wins to begin a season.
Darius Garland scored 25 points while Evan Mobley had 14 points with seven rebounds.
Jared McCain had a career-high 34 for the 76ers, who played without Paul George and Joel Embiid on the second night of a back-to-back as part of left knee injury maintenance. Kelly Oubre Jr. had 20 points while Caleb Martin added 18 for the Sixers.