The Spaniard watched his side miss a number of chances before falling behind, but he admits that it is a relief to still have their future in their own hands after such a disappointing result.
"We cannot face more reality than today," Riga told reporters. "We had control of the game, but we have to score before we concede. We conceded a goal from their only opportunity in 45 minutes.
"We have young players so maybe it's the pressure of the situation. But we still have destiny in our hands. They needed to win, we did not."
Charlton are one point clear of the relegation zone with five games left in the season.