"The so-called 'golden generation' were not playing today. There were young players who showed that they are ready to contribute into that 'new' golden generation. Remember, we are a nation of 11 million people and we keep producing players of a very high level. They really enjoy playing and want to take the nation as far as they can," Martinez said.

He added that the team will now focus only on Japan to avoid avoid temptation to look too far ahead.

"In World Cup you cannot hope to get an easy path. You need to try to create a group, where everyone is in sync, everyone desperate to perform. We had a lot of positive [moments] today," Martinez said.

Belgium qualified top of the group G after beating England 1-0, with midfielder Januzaj scoring the only goal of the match in the 51st minute. They will now face Japan in Rostov-on-Don on July 2, while England will take on Colombia in Moscow the next day.