Despite climbing out of the relegation zone with the win, the Belgian admitted that it was only a small step towards his target after replacing Chris Powell at the club last week.
"To be good with the fans I have to take points first," Riga told reporters. "We will see how valuable that goal is at the end of the season.
"Of course I am happy. I knew when I arrived we would have to work hard and find solutions together and finally we found one.
"At this moment we are out of the bottom three. We deserved to win but it's only one step."
Charlton host promotion hopefuls Burnley in their next game on Saturday afternoon.