Sergio Aguero scored four times for the Premier League champions to condemn Spurs to defeat, and Chadli admits it was frustrating to see a number of good opportunities, including a missed penalty by Roberto Soldado, wasted by the visitors at the Etihad Stadium.
"There were some moments that could have changed the game and going forward we created chances, but we had to get more control of the game," the Belgian told Tottenham's official website.
"We looked very dangerous when we were attacking but it's not enough. We have to be sharper and score the goals."
Spurs are currently ninth in the Premier League.