By ESPNSTAR.com staff
Atletico are favourites to join Real Madrid and Barcelona, who also secured first-leg victories against Valencia and Malaga, in the semi-final after notching a win against Betis at the Vicente Calderon.
They play the return leg at Betis in a week's time and expect it to be a relatively straightforward affair as Betis were restricted to just 38% of the possession in Thursday's game.
Simeone, however, pointed out that Betis are still a good side and, as the fourth-ranked team in La Liga, should not be underestimated in the reverse fixture.
"Betis is a great team, plays very well and are dynamic and quick," Simeone told reporters in the post-match press conference.
"We had a great first half and it was a good result, but far from definitive.
"We had a great first half but in the second we sat too far back and they created opportunities.
"We are facing the fourth ranked team in La Liga;. Today [Thursday] we played a very good match, but in the first half, we played the match we needed to play and in the second we played as a result of what happened in the first."
The Argentinean was especially happy with the performance of goalkeeper Thibaut Courtois as the custodian kept a clean sheet despite 11 shots on goal by the visiting side.
"Courtois was very good, he allowed us to get the win. As always, when a team wins, it comes down to the actions of the goalkeeper."
Los Rojiblancos return to league action with a game against Levante on Sunday before travelling to Seville to play Betis at the Estadio Manuel Ruiz de Lopera.