It meant two wins in a week for the Dutchman.
On Joao Mario, De Boer stated: "Joao Mario a leader? Yes, he is an important player because he runs a lot, not only has the quality to attack, but to defend, he is a player I'm very happy with.
"Now all our players follow my philosophy, we always want to press and dominate the game.
"Today we have done pretty well."