Jordan Ayew, Stephy Mavididi, Wilfred Ndidi and Harry Winks struck the goals to give Cooper a first win as Leicester manager.
“The objective obviously is to get through to the next round and do it with a good performance and I thought that was the case,” Cooper said. “The most important thing is to win and play well. We had real dominance from start to finish.
“We could have been more of a threat in the first half for all of the good positions we got into. Jordan made it happen with his goal, which is obviously a wonderful strike and good for him to get off the mark on his debut, but we needed more moments in the final third, whether it was one vs. one or combination work.
“Skippy and Wilf did get in, so we could have been more than one goal up, but the challenge was to continue to play as we were and where we were playing our football, get good numbers ahead of the ball and then be more of a threat on the goal.
“They really took that on in the second half and were good for the three more goals and the numerous chances, but the expectation is to play well. That starts with the right attitude, and I think we showed that mentality in the game tonight, which should be non-negotiable.”