Charlton have won just once in their last 14 games and wins for their nearest rivals left them six points adrift of safety.
But Charlton boss Riga said: "We started well and we grew into game as out confidence grew. Cardiff deserved to win the game, but for me the most important was to see a reaction from my players.
"We need this kind of commitment. The way we played pleased me a lot.
"Now we must make sure we keep this up in the next game. I saw some very good stuff as Cardiff are a good team and the players' reaction from losing our last home game was important.
"A point is never good enough. With these efforts we will get what we deserve.
"If we want commitment from the fans it starts on the pitch. I'm realistic. Results have not been the best, but what can we do? If you think and act like a team you can do a lot things. I believe in work, commitment and I always stay optimistic. It's a step forward."
Cardiff, who have play-off aspirations, will feel this draw was two points dropped. They hit the woodwork twice through Joe Ralls and Anthony Pilkington in either half.
And Stephen Henderson was the busier of the two goalkeepers, making saves from Sammy Ameboi, Pilkington and Ralls.
Charlton could have stolen the win late on, but for Bruno Manga clearing Simon Makienok's shot off his own line.
Cardiff, who saw Ameobi sent off for a second yellow card late on, are five points off the top six and manager Russell Slade said: "We were open at the end with four strikers on the pitch in an effort to get three points rather than one.
"We had 22 shots and our only criticism is that we had three or four shots on target.
"We were in good situations, but it was our final shot or pass that let us down from time to time.
"There was some really good football and we took control of the game at the start of the second half and played some really good stuff.
"Charlton worked hard and we played a team fighting for their lives. Our two centre-halves were excellent.
"We will still keep fighting and pushing on. We just didn't have that final ruthless streak.
"To have goals in your teams is massive and we have lost goals which is important. But we have strikers we think that are still very capable and have just joined club."