GARY Rowett admitted Leeds United taught Millwall a "lesson" and said Marcelo Bielsa's side were the "best we've played by far" after the Lions lost a two-goal lead at half-time at Elland Road on Tuesday.
Leeds handed Millwall just a third league defeat in 16 league games since Rowett took over in October.
Millwall were two goals up by the 23rd minute after Shaun Hutchinson's header and Jed Wallace's penalty.
Patrick Bamford pulled a goal back three minutes into the second half and Leeds scored twice in four minutes through Pablo Hernandez and Bamford again to go 3-2 ahead 66 minutes in.
It meant the Lions missed out on going sixth, with the result putting Leeds top of the table.
"There's disappointment but overall I think we were given a bit of a lesson today," Rowett said. "Leeds were thoroughly deserving winners and by far the best side we've played.
"Their 10 games without a game benefitted them far more than us playing a Premier League side three days ago. You could see that energy and running in evidence.
"Nevertheless there were probably too many opportunities for them to run past us and into good areas. In one situation in the second half I think [Ezgjan] Alioski runs past four of our players. For me that's not acceptable and we've got to learn that lesson.
"We go 2-0 up, albeit a little bit undeservedly, through a good set-piece and then we get a penalty that for me is a definite penalty, Jon Dadi Bodvarsson gets pulled down.
"I expected a little bit more second half because we didn't perform well enough even in that position we were in. We concede a really poor goal from a set-piece, I think it's [Jack] Harrison gets the wrong side of our defender. If you're going to get anything here you've got to do the job properly in those situations. It's not as if we've been cut open in open play, it's a set-piece.
"Second goal is a deflection and a bit of fortune that they probably deserved. The third goal is a cross where we stand off the crosser and Bamford gets free against two of our big centre-halves in the box which again shouldn't happen.
"We created some other opportunities in the game on transitions when we did cross the ball, but we didn't pass it well enough."
Referee Darren England was booed off at half-time after the home fans felt he had favoured the visitors. Rowett thought he should have awarded his side a spot-kick late on when Matt Smith appeared to have his shirt pulled.
Rowett said: "I think there's a blatant penalty towards the end on Matt Smith, he gets his shirt pulled. I've watched it three times, it should be a penalty.
"What I would say is at that point in the game with the atmosphere the way it was I think it would have been a very difficult decision to give. It should have been a penalty but I can understand in some way how the referee perhaps felt the better decision was to leave it.
"Leeds get a little bit of fortune with that one."
There were unsavoury scenes after Wallace's goal, when several objects landed near the celebrating Lions players.
Rowett added: "I saw Jed hand something to the referee at one stage but I've not asked him what it was. I've not spoken about that.
"I've been here as a player and been 3-0 up after 25 minutes with a Derby side and lost 4-3. It's the type of atmosphere where you can't afford to concede that goal just after half-time, because you know what's going to come and it's going to be a very difficult second half here.
"It proved to be exactly that."
Image: Millwall FC