Alonso was pleased with how Madrid controlled the game while also keeping something back for the weekend trip to Real Sociedad.
"It's obvious our intention is to have a strong start to the game," he said. "Things are always easier when we score first.
"We gave a great performance in the first half and strained ourselves less after half-time because we'll play another game on Saturday.
"We are controlling our fixtures increasingly more and we are gradually reading them better.
"We showcased a fast game and we also kept possession for longer periods of time in which we knew how to read the game.
"This means the team continues to grow and that's a good sign. The team is ambitious and will continue to do things better."