Millwall moved six points clear of the relegation zone after a 3-1 win over Sheffield United.

Goals from Lee Gregory, Mahlon Romeo and Jake Cooper handed the Lions a convincing victory, which ended their six-game winless run.

Here are five things we learned…

Mahlon Romeo gives Neil Harris a selection headache

In his first league start of the season, and his full Championship debut, Romeo couldn’t have done any better.

He scored the second goal of the game to give Millwall a crucial 2-1 lead - and always offered a strong attacking threat on the right, while defending well.

He was ball-watching for the Blades’ equaliser, however, he’ll only get better defensively with more coaching.

Romeo started in place of the suspended Conor McLaughlin, and has given Neil Harris a selection headache ahead of their trip to Aston Villa next weekend.

Lee Gregory responds to his critics

He was on an eight-game scoring drought coming into the game and was left out of a few starting line-ups.

He’s been criticised by Millwall fans for not finding the net as often as last season, but he reminded everyone of his quality in a man-of-the-match display against his boyhood club.

Gregory’s smart turn and finish put Millwall ahead in the 14th minute and he won the ball back to set up Romeo for the second.

Hopefully, this is the start of a purple patch for the Lions’ number nine.

The six-point cushion is vital with tough fixtures to come

Millwall’s next four games are against promotion hopefuls Aston Villa, Middlesbrough, Derby and Wolves.

They are six points clear of 22nd-placed Birmingham, who play Championship leaders Wolves on Monday evening.

So it was extremely important to beat Sheffield United.

And that cushion is going to be crucial during their tricky run of fixtures.

Strong defence continues to impress

Millwall’s back-four contained the Championship’s top scorer Leon Clarke with ease and the Blades rarely troubled Jordan Archer.

Jake Cooper and Shaun Hutchinson were very solid against a free-scoring Blades side.

The loss of Byron Webster was a huge blow, but those two have stepped up in recent months.

Millwall can mix it with the big boys

At the Den, the Lions have laid waste to Birmingham, Leeds and Sheffield United - three massive clubs in the division.

They welcome Middlesbrough, Wolves and QPR to SE26 over the Christmas period, with the chance of surprising some more clubs this season.