Goals from Premier League pair Vincent Kompany and Jan Vertonghen handed Chris Coleman's side defeat on Friday and the home nation were forced to play for over an hour a man down following James Collins's sending off.
Despite the result, Ramsey was encouraged by Wales's performance and believes that a repeat display on Tuesday could earn them their first points of the campaign.
He said: "Overall we are delighted with how we defended and counter-attacked against Belgium and it was a shame we couldn't get a couple of goals, but it is always difficult when you are down to 10 men against a good side.
"But that game has gone now, we can't dwell on what's happened. We have to move on from it, we felt a couple of decisions went against us like when they scored off the free-kick, but we can't do a lot about it.
"I felt we played well, we defended well and hopefully we can do that tomorrow and play with 11 men for the entire game and have a better opportunity to get a result."
Serbia began their own campaign with a 0-0 draw to Scotland.