It was better than beating Man City and Everton
He even believed it eclipsed victories against Manchester City and Everton.
Mr Corney (pictured) said: "I would say it is probably the best as we were at home and also against the biggest club we have played and knocked out.
"We deserved to win and weren't lucky as we scored three goals.
"Matt Smith was tremendous as was everybody. Nobody had a bad game so it is up with my best moment."
He continued: "Rather than talking about relegation the whole time, it is a massive lift for the club and for the town.
"The finances are handy but we would have got through the season with or without the cup run. Now we get through it easier."
He said: "It was fantastic, not just for me but also for the fans, everybody who works at the club and also for the town.
"The place was rocking and I have no doubt the atmosphere gave the players a lift."
Mr Corney added that the performance against the Premier League giants also frustrated him.
He continued: "At the same time I told the manager it is frustrating that the players proved they are good enough.
"I am not saying necessarily to play like that level week in, week out but certainly to a much higher level than we have been."