Millwall blew a two-goal lead to start their Championship campaign off with a draw against Middlesbrough on Saturday.

Aiden O’Brien gave the Lions the lead after 12 minutes at The Den in what was the club’s 25th-anniversary celebration since moving to their new ground back in 1993.

Lee Gregory doubled the host’s lead on 37 minutes, slotting home after Boro defender Aiden Flint’s headed backpass was too short for goalkeeper Darren Randolph to take.

Neil Harris’ men were cruising to an impressive victory over Tony Pulis' side until Martin Braithwaite scored what looked to be a consolation goal three minutes before time.

And in the seventh minutes of five added on, George Friend poked home after Millwall failed to clear a Ryan Shotton long-throw.

Having seen a two-goal lead slip, Harris and Millwall will need to learn from the draw if they are to have a successful season.

But after the two sides shared four goals, here are three things we learned about Millwall after their draw with last season’s play-off semi-finalists.

The first 88 minutes of Millwall’s season carried on how they had finished the previous one.

The structured, organised nature of the Lions team were hard to break down and looked to counter when possible.

With no players leaving, the current crop all know their jobs and are well drilled in what they have to do.

They almost surprised a bigger team in the division once again, had it not been for the late lapses at the back.

If the Lions can replicate the majority of that performance throughout the season, then they will be relatively successful.

Neil Harris’ men were organised and focused for 88 minutes of Saturday’s season opener. 

In the build-up to Boro’s first goal, they lacked the concentration and discipline to just get rid.

Mahlon Romeo dawdled in possession, allowing a Middlesbrough player to hook his foot around the defender and fire the ball into the path of Braithwaite to poke home.

The equaliser came from a long throw. The Lions half cleared the initial ball in but subsequently could not retain their organisation at the back when a Boro onslaught resulted in the goal.

More to the point, Millwall need to add to their front line.

In defence and midfield the Lions have substantial competition for places, but in the final third they are lacking.

This was evident once goal scorer Lee Gregory and captain Steve Morison were substituted, and Tom Elliott came on.

The substitute was unable to hold the ball up when needed and had a glorious chance to extend the Lions lead prior the equaliser. 

There needs to be more quality competition up front if Millwall want to improve as a club and Harris should be backed to bring in a new number nine.