Chris Taylor struck a 70th-minute equaliser as Millwall edged a point closer to Championship safety with a battling draw at Birmingham City.
Wes Thomas had fired the hosts into a 49th-minute lead with a smart shot on the turn past David Forde - the first goal Millwall had conceded in six games.
However Taylor, back in the starting line-up after missing a couple of games through injury, produced a composed finish from Rob Hulse's excellent pass to grab a leveller The Lions so deserved.
It was certainly a game that Taylor will not forget in a hurry as the Millwall midfielder was denied a clear penalty, was then booked, saw Richard Chaplow's 'goal' disallowed amidst much controversy and then finally cancelled out Thomas' opener to secure a share of the spoils.
"It was eventful and there were a lot of big decisions in it," said Lions boss Kenny Jackett. "Overall I'm very pleased that we came from behind to get something out of the game. We haven't done that enough this year.
I was disappointed with the goal, but you can't stop everything. We've conceded one goal in six games and we could've been better defensively overall today but Birmingham have some very good forwards."
Speaking about the penalty and goal that weren't given, Kenny added: "Chris is adamant that there was contact, but you can't really tell on the DVD because it's taken from the same angle that I was at.
As for the disallowed goal, the linesman put his flag up for offside, the referee over-ruled him and gave the goal. The fourth official through his ear piece said that Richard Chaplow was offside and touched the ball so cancelled it.
Overall it was the right decision, but I've never seen a decision changed like that though."
Jackett made four changes to the team that started against Ipswich with Taylor, Rob Hulse Liam Feeney and Sean St Ledger replacing Andy Keogh, John Marquis, Jermaine Easter and Jack Smith.
It was a bold move by The Lions boss, who was determined to find a combination of defensive steel and cutting edge up front, the latter of which had seen his side score just twice in their previous three games.
Whilst it was difficult not to have one eye on next Saturday's FA Cup Semi Final against Wigan Athletic, Jackett had re-emphasised before this game the importance of getting points on the board to help move the team away from the relegation zone.
Lee Clark's Birmingham, themselves casting an anxious glance over their shoulder at the teams below them in the Championship table, showed just one change to their starting line up with Jonathan Spector taking the place of Shane Ferguson in midfield.
With such crucial league points at stake this game had a lot riding on it and it was Millwall who had to do the early defending as Birmingham made a bright start.
Lions keeper David Forde made an important save with just three minutes on the clock, diving low to his right to parry Thomas' goalbound effort away and just two minutes later did well to push Nathan Redmond's looping freekick over the bar for the first corner of the game.
Although The Lions dealt with that comfortably, it was Birmingham who certainly looked livelier in the opening exchanges.
Blues went close again when some great work by Redmond saw the winger's cross flicked on by Nikola Zigic to Ravel Morrison, who hooked over from eight yards.
The Lions began to settle into their stride with Taylor and Feeney both despatching good deliveries that keeper Jack Butland collected in the Birmingham goal.
The first talking point of a highly contentious opening half came on 17 minutes when Taylor raced to intercept a wayward pass and was sent flying by Curtis Davies. Referee Keith Hill waved away the penalty appeals and to add insult to the injured Lions player, then booked him too.
Just three minutes later came one of the most bizarre sequences of events witnessed at a game in recent years. Feeney's cross was met by Taylor and with the ball just about to cross the line, Richard Chaplow made
sure with the feintest of touches. Some three to four seconds later the linesman's flag shot up to rule out the effort for offside, only for referee Hill to award a goal. Following further discussions the effort was struck off again, only for Hill to then indicate a goal and some four minutes after the 'goal' had originally been scored, decide that it would not stand and instead he awarded a goalkick to Birmingham.
Credit to The Lions who, although obviously upset, channelled their disappointment and disbelief into a stirring display thereafter.
Goalkeeper Forde made a magnificent save on 34 minutes, somehow keeping out a stinging first-time shot from Thomas as he connected with Paul Caddis' delivery from the right.
At the other end Butland did well to save Liam Trotter's glancing header and then a neat move involving St Ledger and Taylor saw the latter's cross plucked out of the air by Buckland under pressure from Hulse.
Birmingham were forced to make a change in first-half injury-time when Spector was stretchered off after appearing to land awkwardly and was replaced by Callum Reilly.
The home side started the second half just as they had the first and Forde was called into action to make a smart stop from Morrison.
But Birmingham finally became the first team in six games to penetrate the Millwall defence when Thomas turned on a sixpence and drilled a low shot past Forde to put the hosts ahead.
Rather than steam forward in search of a second goal, Birmingham seemed at a loss what to do and it was Millwall who took the game to their opponents.
Twice wayward back passes from an increasingly jittery Blues rearguard were inches away from the boot of Hulse and Jermaine Easter, who along with Martyn Woolford had entered the fray just before the hour-mark for Chaplow and Feeney.
Following a spell of concerted spell of pressure Millwall finally got the goal that their persistence and effort deserved.
Hulse was the provider with an intelligent cross from the left and there was Taylor, cool as you like, to take one touch to control the ball before firing an unstoppable drive past Butland and into the back of the net.
Birmingham were at sixes and sevens and just moments later a delicious delivery from Alan Dunne was met by St Ledger, whose powerful header rattled the crossbar before the danger was cleared.
A superb piece of improvisation by Easter so nearly came to securing all three points for Millwall, hooking a shot over his shoulder and narrowly over the bar following more good work by Hulse.
But in the end The Lions had to settle for one point that increases the points cushion with the bottom three and extended the unbeaten run to a solid six matches.
Butland, Caddis, Davies, Robinson, Hancox, Redmond, Spector (Reilly, 45+2mins), Morrison, Elliott (Arthur, 78mins), Thomas, Zigic (Lovenkrands, 89mins). Subs not used: Doyle, Caldwell, Mullins, Ambrose.Birmingham City: