Kenny Jackett says there is no chance of Millwall taking Luton's threat lightly ahead of their FA Cup fifth round meeting on Saturday.
Both sides beat Premier League opposition to make it to the last-16 and Jackett says that proves Luton are more than capable of adding another name to the list of giant-killing efforts the competition is famous for.
The Blue Square Bet Premier side have been struggling in the league since their win over Norwich but Jackett is still expecting a close game at Kenilworth Road.
"We won't be underestimating Luton in any way, shape or form when you see them beating the calibre of Norwich and Wolves this season," Jackett said.
"It (Norwich) was a great win, I've watched the game and Luton went to Carrow Road and they played very, very well on the day. It was a fantastic performance, they got their goal when they needed to and defended well.
"What we have to do is recognise this opportunity and do our homework, make sure that in no way do we underestimate our opponents, which we don't do.
"After that we have to put on a performance that gives us the best chance of getting through.
"We understand it is cup football and it's all on the day and a one off occasion, but performances generally look after results.
"We have to concentrate, stay level-headed and identify the key things we do well and if we do that then the performance I'm sure will be fine. All of our focus internally is on that Luton game and the carrot and incentive is there with a quarter-final place for the winners.
"I think you have to ignore it and just concentrate on the game. It is a tricky tie for us and it is not an easy one but there wasn't going to be an easy tie."
What will be the outcome in the match Luton vs Millwall?