Cornick proved to be a big performer today, but another big factor for Luton was the form of Croatian goalkeeper Simon Sluga. He was particularly active in the second half and most notably saved a Jed Wallace penalty and a Matt Smith effort late on to keep his side's two goal deficit.
Sluga's efforts rewarded him and his side with a sixth clean sheet this season, now the best in the league.
Millwall were a team unchanged coming in to this game, after their previous away win at Barnsley. Manager Gary Rowett went for the same defensive set up as the back three of Jake Cooper, Shaun Hutchinson and Dan Ballard had been solid performers in the away clean sheet. Also, the Wallace namesakes continued in the side. Notably, Murray Wallace's goal two weeks ago that sealed the win in South Yorkshire, was set up by Jed.
Millwall: Bialkowski; Ballard, Hutchinson (C), Cooper, McNamara, Evans, Saville, Wallace, Wallace, Ojo, Afobe.
The visitors Luton had only one change. Luke Berry dropped to the bench for Pelly Ruddock Mpanzu. The bench also included some returns from injury for the Hatters. Ex-Millwall winger Fred Onyedinma was included, as was summer singing from Leicester City Admiral Muskwe. The Zimbabwean had played in a development friendly against Bournemouth during the international break and scored - perhaps swaying Nathan Jones' selection decision.
Luton Town: Sluga; Bell, Lockyer, Bradley (C), Naismith, Bree, Mpanzu, Rea, Clark, Cornick, Adebayo.
Referee: Christopher Cavanagh.
Story of the match
Under the floodlights of the enigmatic New Den, Millwall broke out of the nervous early exchanges with the first chance of the game. Eight minutes in, the Lions got in behind as Luton were adamant of offside. Jed Wallace slipped through, but gave little for Simon Sluga to do as his shot was straight at the Croatian.
The hosts would be kicking themselves just three minutes later, as the Hatters broke the deadlock. Some smart build up down Luton's right wing came after James Bree latched on to a loose Jake Cooper header. He found Jordan Clark and the winger put in a lovely ball for Harry Cornick. The forward struck first time with a sweet right foot effort which cannoned into the top right corner.
Cornick would be involved again in another big chance for the away side, as good interplay saw Adebayo turn away from his man in the centre of the park and find James Bree. The right back crossed for Cornick, but Dan McNamara did enough to usher the ball out for a goal kick at the back post.
Luton Town continued to push on but they could only muster a half chance. On 21 minutes, Jordan Clark got under his shot and it was blazed high over the bar. After this, it was Millwall's time to react. McNamara found Benik Afobe and the seasoned striker was unlucky as his effort was blocked well by the recovering Bree.
Now, it seemed the home team had grown in to the game. Liverpool loanee Sheyi Ojo was making mischief for Millwall as he forced two consecutive blocks from Tom Lockyer. The winger seemed unrelenting, but the Welsh international was wise to the trickery and put his body on the line 28 minutes in.
A short while later on the 34 minute mark, Millwall came back again after they forced a corner. Defender Jake Cooper was unmarked and rose well but nodded just wide - harmlessly left of Sluga's goal.
Four minutes later, Luton were caught out for a second time by a ball over the top. However, again Millwall couldn't make the most of it - as Sluga gathered a harmless cross. Half time was signalled and a chorus of boos rang out as Luton went in to the break leading.
Luton opened the second period well and didn't take long to double their lead. It was the familiar combination of the previous goal. Jordan Clark was involved again and found his striker on the edge of the Millwall box. Cornick took the ball superbly and slotted his effort past Bialkowski smartly into the bottom left corner for his 6th goal of the Championship season.
The away side looked to be in the ascendency now and coming forward again in the 58th minute Pelly Ruddock Mpanzu struck the bar with an emphatic effort. Bartosz Bialkowski was rooted to the spot as he watched the ball clatter the woodwork before the defence could head home safely.
As the game entered the final 20 minutes, Millwall were still determined to get a goal back. Simon Sluga was forced to make a smart save from a Jed Wallace free kick, although admittedly it could have been deemed a camera save.
Two minutes later on 75 minutes, Luton brought in another change - Jordan Clark made way for Henri Lansbury. Later, Admiral Muskwe also came on for Elijah Adebayo. Millwall mirrored this with changes too: Ben Mitchell came on for George Evans in midfield and Mason Bennett repaced Benik Afobe. Both sides also utilised the concussion substitutions too.
The last ten minutes offered up a tense affair and this was capped by Millwall's award of a penalty in the 82nd minute. A high ball came in and just evaded the Millwall attackers. The recycled cross caught the hand of Kal Naismith and was deemed handball by Christopher Cavanagh. Jed Wallace stepped up. However, Simon Sluga saved brilliantly to keep the two goal deficit. Diving down low to his right, it was a great composed save late on.
The subsequent corner from this save was cleared, but Luton were scrambling at times. On 85 minutes, Town suffered a self inflicted near miss as Captain Sonny Bradley almost converted in his own net, just flicking the ball wide.
Luton were firmly on the back foot and Sluga was forced into yet another fine stop, desperate for the clean sheet as Millwall piled on the pressure. Luckily for Luton, they had held out just enough and the final whistle would have been a welcome sound to the joyous 1,631 away fans in attendance.
This win put the Hatters 10th and resulted in their sixth clean sheet of the season.
For Millwall, it wasn't such a positive end. In the last ten minutes, the fans were filtering out and now, the side has slipped down to 14th place in the table.
Star performers in this game have to be Harry Cornick and Simon Sluga. Cornick has extended his scoring form that seemed electric in the win against favourites Coventry and his two goals today mean he is now Luton's top scorer with six goals this season.
Sluga was integral today and his penalty save was the eye catching poster child for an impressive all round goalkeeping display. Another Luton player, that should also be considered is Jordan Clark. Him and Cornick presented a great dynamic and he assisted the ex-Bournemouth man in both his goals.
For Millwall, what was noticeable was that despite their best efforts, they seemed pretty blunt this afternoon. Although wingers Ojo and Wallace offered consistent attacking options, it was the final effort today that was just awry - Benik Afobe seemed a shadow of his former self. Additionally, they built out from the back poorly and it seemed common place for goalkeeper Bartosz Bialkowski to misplace a kick.