Mitchell also came through in a pivotal moment late in the fourth quarter to force overtime after being fouled with three seconds remaining, trailing by three. He made the first free throw, before missing the second and getting his own offensive rebound and putting it back in to tie the game.
He went on to outscore the Bulls 13-4 by himself in the extra period, finishing 22-of-34 from the field, seven-of-15 from deep and 20-of-25 from the free throw line while adding 11 assists and eight rebounds.
Mitchell blew his own career-highs out of the water, having never previously scored more than 46 points in a regular season game, although he had games of 57 and 51 in the Utah Jazz's 2020 playoff series against the Denver Nuggets.
He scored or assisted on 99 of the Cavaliers' 145 points – the second most all-time, trailing only Wilt Chamberlain's 100-point performance in 1962 where he contributed to 104 points.
Mitchell joins Chamberlain, Kobe Bryant, Elgin Baylor, David Robinson, David Thompson and Devin Booker as the only players to reach the 70-point figure.
It overshadowed a terrific performance from Chicago's DeMar DeRozan, who scored a team-high 44 points on 16-of-32 shooting with four assists and four steals.
LeBron carries the Lakers in vintage display
Los Angeles Lakers superstar LeBron James willed his side to a 121-115 road win against the Charlotte Hornets with his second consecutive 40-point game.
After putting up a season-high 47 points his last time out against the Atlanta Hawks on Friday, James almost matched it against Charlotte, scoring a game-high 43 points on 16-of-26 shooting with 11 rebounds and six assists.
He was the only Lakers player to score more than 18 points, as Thomas Bryant played strong supporting role with 18 points (nine-of-17 shooting) and 15 rebounds.
The Lakers have now won three of their past four to improve to 16-21 – four games behind the Sacramento Kings (19-16) in the Western Conference's sixth seed.
Nets make it 12 in a row
The Brooklyn Nets own this season's longest winning streak after rattling off their 12th in a row with a 139-103 drubbing of the San Antonio Spurs.
Brooklyn's two offensive centrepieces were both at the top of their game. Kevin Durant scored 25 points on wildly efficient 10-of-14 shooting with 11 assists, while Kyrie Irving scored his game-high 27 points on 11-of-14 shooting.
The highlight of the game came when Irving crashed the offensive rebounds on a Yuta Watanabe miss, rising up for a surprising put-back dunk that sent the Barclays Center crowd into raptures.
Brooklyn are now 25-12 after beginning the season 1-5, and trail the Boston Celtics (26-11) by one game in the race for the league's best record.