Jose Mourinho celebrated a year in charge of Spurs with a second straight win over old rival Guardiola, who was hoping to mark his new contract with a positive result but has now lost all three of his games at Tottenham Hotspur Stadium.
Son converted a Tanguy Ndombele pass after five minutes on Saturday and Mourinho's men, who spent much of the intervening time on the back foot, sealed the triumph when Lo Celso beat Ederson with 25 minutes remaining.