Paul Robinson headed a 75th-minute equaliser as Millwall moved into the automatic promotion places for the first time this season after a fiercely contested derby against Brentford.
Skipper Robbo was perfectly placed to convert Tony Craig's inswinging corner to cancel out Carl Cort's controversial opener for The Bees that was clearly offside.
Brentford, fresh from a 3-2 win at Oldham on Tuesday night, produced a well-drilled display to repel what at times proved to be relentless pressure from the home side.
Boosted by a bumper Good Friday crowd of 14,025, Millwall started with real purpose and could have taken the lead on eight minutes when Chris Hackett's delightful dinked pass was picked up by Morison, whose lob was brilliantly blocked by Bees keeper Wojciech Szczesny.
Karleigh Osborne was booked just seconds later for a clumsy challenge that caught Morison. Hackett's subsequent free-kick was played square to Craig, who punted the ball forward into the danger zone for Liam Trotter. The midfielder's goalbound shot was blocked and then appeared to be handled by Ryan Dickson to prevent Trotter connecting with the loose ball.
Hackett drove narrowly wide and then a sublime Neil Harris chip clipped the woodwork as Millwall continued to search for the opening goal.
But it was Brentford, temporarily down to 10 men with Kevin O'Connor off the field receiving treatment, who took the lead on 32 minutes.
Former Wimbledon and Newcastle United striker Cort was clearly offfside when he picked up a hopeful forward punt from Osborne.
The powerful frontman sprinted forward and despatched a firm shot beyond the reach of keeper David Forde with the linesman's flag inexplicably staying down.
Spurred on by a vociferous home crowd - and a real sense of injustice - The Lions continued to ask questions of the visiting rearguard.
Trotter's header from a Hackett delivery was deflected for a corner and then Hackett himself dragged a shot wide as Millwall tried to get back on level terms before the break.
Kenny Jackett's charges picked up where they left off after the restart with Trotter's 18-yard drive held by the Szczesny in the visiting goal before the on-loan Arsenal keeper produced a brilliant tip-over to deny Danny Schofield's angled effort.
Robinson then sent a header over the bar from a Hackett corner - one of 15 that The Lions chalked up during the game - before producing a magnificent defensive tackle at the other end to nick the ball off the toes of Charlie MacDonald as he prepared to shoot from 10 yards.
Harris was thwarted on the line by the keeper, and Shaun Batt, a 70th-minute replacement for Hackett, saw his first-time 75th-minute rocket superbly parried by Szczesny.
By this stage Millwall were battering Brentford, and Jackett's men finally got the goal their dogged determination deserved when, from the resulting corner, Craig's deep delivery was firmly headed into the back of the net by Robinson.
Morison was a whisker away from connecting with another teasing cross from Craig as the game headed towards the 90 minute mark.
The Lions were left wondering how they didn't add a second goal in the dying seconds of normal time when great work by Schofield on the left saw the midfielder wriggle his way into the area before picking out Batt in a central position. Unfortunately the young sub failed to get the necessary direction on his header and the ball flew sideways instead of into the roof of the net.
Four nervy minutes of injury-time followed, during which a couple of quick breaks from The Bees lively sub Lionel Ainsworth produced real heart-in-mouth moments for the home fans.
Thankfully Ainsworth's speed of thought didn't match the quickness of his feet, and both his forward forays came to nothing.
Millwall: Forde, Dunne, Craig, Abdou, Robinson, Ward, Schofield, Trotter, Harris, Morison, Hackett (Batt, 70mins). Subs not used: Sullivan, Smith, Frampton, Obika, Barron, Laird.
Bookings: Trotter (35mins), Dunne (57mins)
Scorer: Robinson (75mins)
Brentford: Szczesny, O'Connor (Hunt, 34mins), Dickson (Wood, 18mins), Bean, Cort, MacDonald (Ainsworth, 75mins), Weston, Diagourga, Osborne, Balkestein, Legge. Subs not used: Saunders, Foster, Strevens, Price.
Bookings: Osborne (9mins), Weston (71mins), Bean (90+2mins)
Scorer: Cort (32mins)
Ref: Paul Taylor
Att: 14,025 (away 935)