"I am very proud of the players," Riga told reporters. "It was very important to hit back after our last game at home and it was the first of three away games in a row.
"We expected a Forest reaction and a difficult game, but I thought we deserved the three points, we did well.
"Organisation was key and we had that and some quality. In our situation we have to take our chances when we get them and at last we scored. We are all in this together and this was one good step in the right direction."
The Addicks are currently 21st, three points clear of the relegation zone.