Smith scored after coming on as a sub against the Londoners, just as he had at Liverpool in his first senior appearance a week earlier.
Smith said: "It will be the most emotional day of my career because, as everyone knows, I love this club and would definitely have stayed if we hadn't been relegated.
"I think the fans understand that playing for England means a lot to me too and my chances of being picked at international level would be harmed if I was playing in Division One next season."
Smith said: "It will be the most emotional day of my career because, as everyone knows, I love this club and would definitely have stayed if we hadn't been relegated.
"I think the fans understand that playing for England means a lot to me too and my chances of being picked at international level would be harmed if I was playing in Division One next season."