Sevilla defender Sergio Escudero believes Sunday's 1-0 home win over title contenders Atletico Madrid shows the team are becoming stronger.
A Steven N'Zonzi goal ended Atletico's 11-game unbeaten run and stretched Sevilla's winning streak to five games in all competitions.
The result lifted them to second place in La Liga, one point adrift of league leaders Real Madrid, after nine games.
And Escudero told his club's official website: "We are extremely happy. To beat a team like Atletico Madrid, one of the top clubs in Europe and in the world, is good reason to be happy.
"I think this victory against Atletico is a step up."
Sevilla, under former Chile coach Jorge Sampaoli, have lost just once -- at Athletic Bilbao last month -- and won all six of their games at the Sanchez Pizjuan.
Escudero added that Sevilla, with 12 new signings over the summer, had needed to adapt and had shown their character in games such as a tough 3-2 win at Leganes earlier this month.
"All games are very complicated and we struggled against Leganes," the 27-year-old added.
"We have to follow this path, to fight and to play as we know how. We have to demand the best from ourselves in every game."
Sevilla are away to Sporting Gijon on Saturday before hosting Dinamo Zagreb in the Champions League.