Mowbray praised his goalscoring defender for his contribution.

He said: "This team, they have a competitive edge about them. Every single day, they finish training with a shooting drill. One of the players delivers from behind the goal and they have to have a touch and finish. I see Derrick doing it every day. Derrick knows where the back of the net is.

"We've been talking about not enough goals from outside the box. Every week when I go home and watch the goals show on Sky, there's a lot of goals from outside the box and a lot of set plays.

"We don't score enough from outside the box. I think (Stewart) Downing is the only one who has scored from outside the box and it's great that somebody else has scored from outside the box.

"We talked this week about how we are going to score against Millwall, how difficult it is, we talked about getting behind them and cut-backs so the second goal is really pleasing. Typical Dack. A lot of bodies throwing themselves at it as the ball whizzed past, yet he was so pure with his side foot into the net.

"But Derrick Williams, I'm delighted he's scored outside the box, somebody else taking on the responsibility to shoot."

The defeat means Millwall have not won in four, but while Neil Harris conceded his side gave away "poor goals", he accused the referee of "bottling" a decision when his centre half Jake Cooper went down in the area in the second half.

He said: "I will just comment, in the 68th minute – I've seen it back from three different angles – we've got a stonewall penalty from a set-piece when the game's at 1-0.

"The referee talks to Sam Gallagher marking Jake Cooper. Jake gets a run, the player is the wrong side of him and manhandles him to the ground with a rugby tackle. The referee is seven yards away and for me, he bottles it.

"I think the referee bottled it at the end of the day and he has to give that decision. What's the point of talking to a player, and let him get the wrong side? What game are we playing here? We play to win set plays and when you win them, you need some help.

"I was very disappointed to be behind at half-time. I thought it was unjust and we didn't deserve to be behind. The goal is a great strike by a centre half from 25 yards but we should do better in the lead-up to it.

"We gave a really poor second goal away. Players have to do what instructions are given to them, not what they want to do."