Neil Harris has pinpointed Saturday afternoon's 1-0 victory at The Den over Sheffield Wednesday as "one of my most pleasing wins", coming out on top with 10 men for the majority of the contest.
The Owls visited SE16 as Sky Bet Championship leaders, but Matt Smith's goal and a resolute defensive showing after Jed Wallace's first-half red card secured three more points on the board.
"What an effort that was by the players today, I have to say I'm drained after that," Harris says.
"I've been lucky enough to see success here at this club - promotions, Cup runs and Play-Off games - but as a manager, it's one of my most pleasing wins. That is Millwall - backs to the wall, and a real physical Championship battle, and the uglier it got, the better we got in the game.
"When you play with 10 men against good players, it's very tough. We were up against a team who could bring on Barry Bannan at half-time. We rode our luck, yes, but the effort by the boys, their application and the atmosphere in the stadium, it was a Millwall day."
The manager gives his view on Wallace's dismissal, and explains the change of shape following the numerical disadvantage for The Lions.
"We brought off Smithy - who was excellent and got himself another goal - and brought on Bradders for legs and the ability to get after the ball. However we have to change our shape, I said to the boys that it's about attitude and desire, and wanting a clean sheet. The mentality of the whole team to see the game out in that fashion was a great effort.
"The goal was standard from a ball into the box - when you have the likes of Coops and Smithy, Pearcey, Hutch on the bench as well, Murray Wallace... we have to get the service into the penalty area.
"I have to see TV replays for a definitive view on the red card - if Jed's foot leaves the floor it's possibly a red, if it doesn't then it isn't. I need the benefit of seeing the replays a bit closer."
The displays of certain individuals caught Harris' eye, praising the defensive and leadership qualities through the team.
"Mahlon dealt with Kadeem Harris well. There were times when he did get beaten down that flank, but when a player like Harris has no defensive responsbilities then he's a very dangerous winger at this level - getting balls into the box as I would expect from Fergie, Jed, Connor and Jiri.
"Mahlon along with the whole group defensively stuck to their task very well. It's key to have the leadership, and that's what the likes of Pearcey, Bart and Willo bring to the side.
"I know Willo can divide the fanbase in terms of what he brings to the group - although the majority do see his qualities - but he brings leadership and helps the other midfield players. His headers today, his tackles and the timing of his challenges was very good, as with the whole midfield. The defence were outstanding with what they put in for us, and it was a very positive performance - another challenge we've risen to as with previous games this season."
Following a thoroughly satisfying win, Harris finally looks ahead to successive away games in the upcoming week, against challenging opponents in Fulham and Middlesbrough.
"We have two tough games now. Fulham looked very good last night, and they have a top squad - for me, the best starting XI in the division by a mile. We know it will be a tough challenge, but it will be a great atmosphere with us selling our allocation.
"We're the only ones who expect ourselves to get anything, and it's another tough task we look to overcome. After that, we go to Middlesbrough who haven't started well. We have a big opportunity to go up to Boro' and put a performance in next weekend.
"We have to be Millwall-like, pressurise the final third and force set-plays. We've picked up two home wins against two very good away sides, and I can't ask for anymore. It wasn't the best football on display, but it was dogged and we've set our stall out this season for how we have to be in the Championship."