Casanova later paid homage to Capoue, whom he believes has grown as a player since his call-up to the France squad.
"The victory is totally merited. We controlled the match completely and could have won 3-0 or 4-0," said Casanova.
"I am really satisfied with the team as a whole. We were superior to Saint-Etienne over the course of the game and the success is logical.
"As for Capoue, his call-up to the national team has done him a lot of good. He has taken on extra responsibility and grown in maturity. He knows he has a different status now and he has to be irreproachable."
Toulouse travel to Nancy next Saturday.