The Irons had 31 shots on goal, but still ended losing 3-1 at the KPS as Jamie Vardy, Bilal El Khannouss and Patson Daka had the Foxes 3-0 ahead before Niclas Füllkrug scored a late consolation for the visitors.
Van Nistelrooy said afterwards: “I’m very happy. If you look at the result, and it’s about the results, it was a great night. Three points, three goals, and three good goals I think. I was very happy with that. Overall, we all saw the game and how dominant West Ham were at certain stages and how much they created and the attempts they had. That was a fact. It’s something of course we have to look at and do better.
"Overall what I said I expected moving forward was to togetherness a hunger, energy, hunger and spirit who are fighting as a foundation to play the rest of the PL. I saw that completely with every player that starts and came on. That’s the foundation we have to build on without that it will be impossible to get where we want to go.
"The defensive shape is something important and WH has a flexible build up the timing of the press with two or three is quite difficult and needs time and coordination to get right. We did that a couple of times but many times we missed the moment to press and we got pushed back too far and let them in our box too often."