But Hull levelled on 73 minutes as Jordy de Wijs headed Jarrod Bowen's corner back across goal and skipper Markus Henriksen nodded in at the back post.

And while Lions boss Harris was pleased with the overall display, he lamented his side's lack of concentration at crucial moments.

"I thought we dominated from start to finish," said Harris. "Shot count, set-pieces, crosses, aerial duels, foot races, tackles, shots on goal – we dominated everything.

"But the scoreline says 2-2 and that's the bottom line. We can't keep scoring goals at one end and conceding at the other, we have to get back to noughts and ones.

"We conceded one last week and it was an excellent result at Bristol City. We have to get back to that because to come from behind at the Den is not always easy.

"We got ourselves in front and are absolutely dominating the game and then gave them two free headers in our penalty area. Individually that's not acceptable.

"Mentally they've got to be better. When you're defending, you say 'my man doesn't touch the ball, my man doesn't score'. That's all it is. I learned that at a very young age.

"The first goal was poor, a player switches off, and he's put his hand up for it. But the second one was just too easy."

Nigel Adkins was celebrating his one-year anniversary as Hull boss and, unsurprisingly, he was the happier of the two managers at the final whistle.

The Tigers battled gamely and Adkins highlighted the togetherness of his squad as a key to the result – reserving particular praise for 18-year-old full-back Brandon Fleming.

"It's a good point away from home," said Adkins. "Millwall is always a challenging place to come to and we knew that before the game. We knew we had to be competitive.

"It was going to be a big ask, especially when we had young Brandon Fleming making his [league] debut at left-back.

"He's from the academy system. We've had a lot of injuries, I played him and I thought he was superb – he did really, really well.

"We got off to a good start with Kamil Grosicki on the counter attack – it was a really good goal. Then from our point of view, it was a poor goal for the equaliser. We've got to stop the cross coming in.

"Millwall started the second half really well, they pinned us back and it was really challenging.

"They've scored and we've had to hang in there, make a little change and it was a good goal from the corner from Henriksen after the first header from de Wijs.

"It's a good result away from home and underlines the spirit we've got in the team, with all the squad contributing."

ga('create', 'UA-72310761-1', 'auto', {'name': 'pacontentapi'});
ga('pacontentapi.set', 'referrer', location.origin);
ga('pacontentapi.set', 'dimension1', 'By Press Association Sport staff');
ga('pacontentapi.set', 'dimension2', '216766fd-94dd-4b65-94f6-3210ce1ede35');
ga('pacontentapi.set', 'dimension3', 'paservice:sport,paservice:sport:club-news,paservice:sport:football,paservice:sport:match-reports');
ga('pacontentapi.set', 'dimension6', 'story');
ga('pacontentapi.set', 'dimension7', 'composite');
ga('pacontentapi.set', 'dimension8', null);
ga('pacontentapi.set', 'dimension9', 'sport:football');
ga('pacontentapi.send', 'pageview', { 'location': location.href, 'page': (location.pathname + location.search + location.hash), 'title': 'Neil Harris wants Millwall to up their concentration levels after Hull draw'});