Real, brimming with confidence after their statement Champions League win at Manchester City midweek, sit comfortably on top of LaLiga on 78 points, ahead of Barca on 70 and Girona on 65
"Due to recent weather events, tournament organisers and participating clubs have decided to cancel tonight's International Champions Cup game," United said in a statement on their official website (www.manutd.com).
New United manager Mourinho had criticised conditions at the Bird's Nest stadium, where torrential rain had soaked the playing surface, and voiced his concerns on the matter prior to the game.
The match would have marked an early renewal of Mourinho's rivalry with Guardiola, dating back to their days in charge of Real Madrid and Barcelona respectively.