Millwall assistant boss Joe Gallen insists his side kept their composure as they went on to snatch a 2-1 npower Championship victory over Derby.
Liam Feeney had given the Lions a 33rd-minute lead but they were pegged back by Will Hughes' leveller eight minutes after the break.
However, Andy Keogh's strike settled the game 14 minutes from time.
Gallen - standing in for Kenny Jackett, who missed the game with flu - said: "Kenny has just got a bit of flu and he'll be back next week.
"I had an idea on Thursday he wasn't going to make it but carried on with what he was going to do. Kenny picked the team and discussed what training we are going to do and told me what the team needed to do. He was here, but not here.
"The team has been defending and running and working and blocking for the previous nine games. It's been a big feature of our performances. (With) the disappointment of an equaliser after half-time, it took us 10 minutes to compose ourselves and we did well to nick a tight game."
Keogh proved the matchwinner, scoring after returning to the starting XI due to an injury to Lions top scorer Darius Henderson.
Derby youngster Hughes, who earned a call-up to the England Under-21 squad this week, had earlier cancelled out a controversial opener from Feeney and it was the controversy surrounding Millwall's opener which left Derby boss Nigel Clough to question the officials.
He said: "We're not privy to the conversation between the officials and we asked the players not to approach them. The assistant flagged for offside, kept his flag up and was insistent. The referee went over and gave the goal. Why he did that I don't know. Keogh [the player offside] went for the ball and that affects everyone around him.
"We thought we should have had a penalty at the end and one at the end of the first half. We can't control that. We can only control our own performance and we thought we deserved to go in level at half-time."