MILLWALL boss Kenny Jackett admitted his side committed a fatal error in conceding after just three minutes in their FA Cup defeat to Bolton.
Arsenal loanee Ryo Miyaichi latched onto a quickly-taken Trotters free-kick to score with the first shot of the match and leave the Lions facing an uphill task.
And Jackett felt such an early set-back was a hammer-blow his side never fully recovered from.
"It was a poor goal to give away and you can't do that against a Premier League side," he told the club's official website. "Whether it was a foul or not [for the free-kick], is maybe irrelevant. They've taken it quickly and caught us out.
"After that we worked hard to recover our confidence and we had a lot of the ball. The corner count today was nine to one in our favour, and you really have to make that pay. They sat deep and broke at us quickly, and in the end they had enough class to ease us off.
"We've had a good cup run and it's definitely helped us, but have to look forward to what is a massive game against Middlesbrough on Tuesday. It wasn't to be today, although we weren't disgraced."
Jackett also revealed post-match that his decision to drop first-choice goalkeeper David Forde, whose error cost the Lions victory in their 2-2 draw with Brighton last week, was a tactical one.
"David needed a break. He'll come back stronger. Steve Mildenhall is a good goalkeeper and I felt we needed to freshen things up. Between the two of them I'm confident we have enough experience."