Millwall missed the opportunity to move into the Championship's top-six as Louie Sibley scored a sensational first career hat-trick to help Derby County come from behind and claim a 3-2 victory at The Den.

It all started so well for the Lions, who took an early lead through Matt Smith, but 18-year-old Sibley took centre stage by producing three clinical finishes to ensure he went home with the match ball on just his second league start.

Jon Dadi Bodvarsson struck late on, but the Rams held on to record their third consecutive win and join Millwall on 54 points in the Championship standings.

With Preston playing at Luton Town later this afternoon, Gary Rowett's side, who've now gone six home matches without winning in all competitions, could find themselves five points adrift of the play-off places by the time they travel to relegation-threatened Barnsley next Saturday.

Despite a 106 day wait since their impressive victory over Nottingham Forest back in March, Rowett made just one change from their City Ground massacre as Ryan Leonard - in his new found attacking role - replaced Mason Bennett, who was ineligible to face his parent-club.

Frank Fielding, captain Alex Pearce, Ben Thompson and Aiden O'Brien were all absent through injury, meaning 18-year-old defender Hayden Muller was named in the matchday squad for the first time.

After a three-month break, both sides were understandably slow out of the blocks, but the game sprung into life on 15 minutes when Millwall broke the deadlock - with Smith continuing where he left off prior to the suspension of English football amid the Coronavirus pandemic, by notching his 12th Championship goal of the campaign.

Shane Ferguson started the move in his own half and then eventually picked out Smith at the other end of the pitch with a teasing left-footed delivery - and the ex-QPR striker did the rest with a perfectly-placed header past Ben Hamer from six-yards.

The Rams responded well, though, and almost levelled immediately as Martyn Waghorn's free-kick clipped the top of the crossbar with Bartosz Bialkowski beaten.

However, midway through the first-half - and just seconds after the first drinks break - Derby finally got their equaliser. Sibley picked the ball up on the edge of the box and showed great footwork to beat three Lions defenders before blasting into the roof of the net from 12-yards.

Phillip Cocu's men had the wind in their sails and nearly completed the turnaround on 36 minutes - with the impressive Sibley once more in the thick of the action. The teenager found space inside the area and fired towards goal, but this time Bialkowski came to Millwall's rescue with a wonderful one-handed save down to his left.

Despite Derby's masses of possession, Rowett's men continued to look dangerous themselves, and Mahlon Romeo, who hasn't scored since December 2017, tested Hamer before drilling a low effort into the side-netting.

And Hamer had to be at his very best to keep out Ryan Leonard on the stroke of half-time as Smith produced a cheeky nutmeg on former England and Manchester United captain Wayne Rooney before chipping into the path of the midfielder - who was through on goal - but his poked effort was tipped over by the Rams shotstopper.

Millwall had a spring in the step at the beginning of the second period and just four minutes after the break they squandered another golden chance to retake the lead. A quickly-taken throw-in from Romeo put Smith in the clear, but he couldn't keep his lobbed effort down - with Hamer in no man's land.

Up the other end, Craig Forsyth found Sibley, who cut inside, but couldn't keep his shot down from 12-yards.

However, Sibley, who was a thorn in Millwall's side all afternoon, didn't pass up the next chance that fell his way - coolly slotting under Bialkowski after latching onto Waghorn's inch-perfect pass in the 71st minute.

Rowett threw on Bodvarsson, Tom Bradshaw, Jiri Skalak and Connor Mahoney in attempt to salvage something from the game, but the afternoon belonged Sibley, who completed his hat-trick with another superb finish as the clock struck 90 minutes.

Bodvarsson reduced the deficit deep into stoppage-time, finishing in off the crossbar, but it was too little too late for the Lions, who lost ground in the race for the top-six.