Then the cast gathered around with the huge crowds to watch the tournament. The players were very nervous but determined too.
Every time someone scored a goal the crowds cheered, and they went wild if someone caught the snitch!
In the end, it wasn't Britain's day, but the cup went to a very happy Hidenori Tanaka from Japan. "He was ecstatic, he was so happy," a spokesman for makers EA Games said.
But we'll give the final word to Slytherin's star Quidditch player, Draco Malfoy.
"I cant believe they've actually made a game of it," Tom Felton said. "It was a sort of a joke we used to make on the first film, that one day we'd actually be going to a Quidditch World Cup, and now here we are!