Glasner said his players deserved their win at Old Trafford.
He declared: "We defended really well today, we struggled in some moments at the start and after half time.
"We scored from a set-play but had two or three big chances in the first half and we had to keep the belief. We knew there would be moments where we had to survive because every team has this at Old Trafford. Big credit to the team and the players today."
On Mateta, Glasner said: "We don't always talk because he knows what we demand of him. With his two goals today, he is amazing in the box.
"He has the feeling that a number nine must have in the box. He makes so many runs where he doesn't get the ball. You need to suffer as a striker because you make so many runs where you don't get the ball. He gets the reward and it decides the game for us."
"We're just enjoying this moment, a big win. I will enjoy this moment, even if it is a long journey."