Grayson said: "Occasions like this are the motivation to make it happen even more. The crowd and the atmosphere were brilliant and brought back memories of five or six years ago when we were in the Premier League.
"We want to get back to playing Tottenham, Liverpool and Manchester United every week. Over two games against Spurs we have given a really good account of ourselves, and I think people will have seen what we are all about.
"Our main aim is to ensure we get back into the Championship. Time will tell if we can do it, but we now have a good opportunity.
"The league is our bread and butter but we can take a lot from our cup run. The players were really down in the dressing room, but they will feel better about themselves in the morning. That is when they will appreciate what they have achieved."