"To overcome Leeds, who are a very good team, over two legs is a very good achievement," said Jackett.
"It was one of the best atmospheres here tonight that I've been involved in and when their goal went in, there was some momentum there and we came back from that very well.
"There's no secret to our spirit. People look for secrets in football and there aren't any.
"There's honesty, hard work, commitment and at times quality. The start of the second half was really built up and I've got to say they had us under a lot of pressure."
Simon Grayson, the Leeds manager, set his sights on a top-two finish next season."We had plans for Championship football and League One football, we know where we are with players and budgets," he said.
"So we'll get over it, start again and give it a real good go for automatic promotion next season."