The Australian enjoyed a fierce battle with Vidic with the United centre-back at one point forced to leave the field after being caught by a flailing arm from Cahill.
But he said: "The beautiful thing about it is that we both took knocks. When you play against proper professionals like that it is all part and parcel of the game. If anything it makes you a better player.
"The game needs to keep that element, it needs to make sure players are not always falling over trying to draw a foul. We both took a few hits but we both got up. He's a strong boy and there are not many players who like to play against him.
"To get a goal, set one up and be in the rough and tough of it is what it's all about for me."