Appleton said it was a great effort by the heavily changed team to record such a positive result against a club like City.
"It was a great result. Really positive. Made numerous changes and the lads responded well," said Appleton.
"We were second guessing their side bearing in mind they have Chelsea on Saturday but there was still a lot of experience in the side.
"They brought the cavalry on at the end and we were under the cosh for the last 15 minutes but we did enough to win."