The final month of the regular season began with a comfortable 3-1 victory over Scunthorpe United at The Den.
From the moment Shaun Williams dispatched a penalty-kick after just three minutes, The Lions' grip on the game got stronger and stronger and they deservedly raced into a 3-0 lead, courtesy of strikes from Shane Ferguson and Aiden O'Brien.
A tough looking trip to struggling Shrewsbury Town was handled with relative ease on 4th April as the centre-back pairing of Byron Webster and Shaun Hutchinson edged Millwall to a 2-1 win over The Shrews.
A local derby with Gillingham followed and despite Joe Quigley giving the home side the lead in controversial circumstances on 67 minutes, Steve Morison's equaliser just five minutes later ensured a share of the spoils.
A superb Lions side motored into a 3-0 lead once more at The Den on Good Friday against Northampton Town, with Jed Wallace's stunning long-range effort eventually being voted Goal of the Season, but it was back down to earth on Easter Monday as, despite a dominant performance, Millwall fell foul of fellow promotion candidates Fleetwood Town, losing 1-0.
The Play-Off charge looked to have hit the buffers in a 3-0 defeat of Oxford United at The Den, but a remarkable afternoon in Bristol on the final day of the regular campaign secured the club's place in the end-of-season lottery.
With The Lions needing a win to be assured of their place, Lee Gregory and Tony Craig's early goals helped them on their way. Former Millwall striker Jermaine Easter pulled one back for The Gas, but Gregory extended the lead once more just two minutes later following excellent work between the striker and his partner Steve Morison.
But, Chris Lines and Billy Bodin halved the deficit and equalised respectively, leaving The Lions just 15 minutes to find the goal that would take them into the Play-Offs. They found just that with 85 minutes on the clock, as Hutchinson crashed a header home from Ferguson's corner-kick.
A breathless final-day encounter made way for a tight, tense, nervy and goalless Play-Off Semi-Final first leg at home to Scunthorpe United, with the second leg becoming a night to remember in north Lincolnshire, as Morison's double, coupled with Gregory's header, sent Millwall to Wembley for the second successive season in a 3-2 win.
The Lions were to banish the demons of defeat to Barnsley in the Final, as Morison's late winner secured promotion to The Championship in the most dramatic of circumstances.