"I'm delighted. Whether Wigan had half an eye on [this weekend's] FA Cup semi-final I don't know, but you can't argue with the way we played," Holloway is quoted as saying by BBC Sport.
"We moved the ball around well in the first half and we scored a great goal. The second half was different - we were up against it and got a little bit nervous.
"But we hung in there and the last two games have given me a little bit of hope and pride for the future."
Tuesday's win has seen Millwall remain two points adrift of safety in the table with five games left to play.