The Frenchman made a number of changes to his line-up for the third round clash and it paid dividends as the North Londoners put Forest to the sword with a 4-0 victory at the City Ground.
"I knew we had a strong squad," Wenger said.
"It was a full house, a completely motivated team against us and we had a complete performance.
"Technically we played we'll, our combinations were good and we played at a high tempo.
However, Wenger also told arsenal.com that Forest made life difficult for the Gunners in the early stages of the contest.
"We got there in the end but the game was tough, Nottingham Forest played with full commitment," he added.
"We needed to be patient and as well not to concede a goal - which we did well.
"Overall I felt that technically we played well, our combinations worked well and we played at a high pace and that's where we made the difference in the game."