Mauricio Pochettino's side, which won the competition last year, forged ahead in the 31st minute courtesy of Erik Lamela's close-range strike, but the Serie A champion stormed back thanks to goals from Gonzalo Higuain and Cristiano Ronaldo within minutes of each other.
Half-time substitute Lucas Moura pulled Spurs level in the 65th minute before Kane beat goalkeeper Wojciech Szczesny from just inside Juve's half deep in added time.
The match also saw Juventus debuts for big money signing Matthijs de Ligt and former Paris Saint-Germain midfielder Adrian Rabiot.
Spur also showed off their record signing, Tanguy Ndombele, who made an immediate impact as a second-half substitute in assisting Moura's goal.
Spurs continue their preparations for the 2019-2020 campaign against Manchester United in Shanghai on Friday (AEST), while Juve faces Serie A rival Inter Milan in Nanjing a day earlier.