The victory in Seville was just their third league win of the season, while they remain eight points from safety in La Liga.
"We knew there was no choice but to win today and they did, so it was a triumph for the players," Calderon told reporters.
"We've been looking for balance after conceding so many goals in our last games. Today we had organization and balance like never before.
"And Ruben [Castro] is more committed than ever. But we still have room for improvement."
Betis have lost 14 of their 22 league games this season.