Liam Trotter kept his cool to smash home an injury-time spot-kick leveller as Millwall's 10-men battled back to record a fine awayday point at Reading.
The Royals had taken an eighth minute lead through Sean Morrison and when Lions midfielder Jimmy Abdou was shown a second yellow card late on, it looked to be game over for Millwall.
But a crude challenge by keeper Adam Federici on Scott McDonald in the second minute of injury-time handed The Lions a lifeline - and Trotter made no mistake with a fierce finish into the roof of the net for a deserved share of the spoils.
Lions boss Steve Lomas stuck with the same side that started against QPR last Saturday and made just two changes on the bench with Shaun Derry replacing Josh Wright and Liam Feeney, recalled from his loan at Bolton on Friday, returning for Andy Keogh.
Millwall's last two away trips had seen the team ship nine goals at Birmingham City (0-4) and AFC Bournemouth (2-5) so slight trepidation amongst the 1,000 travelling fans was understandable as The Lions faced a Reading side that had smacked four goals past Doncaster Rovers in their last outing at the Madejski Stadium.
The last thing Lomas or his charges wanted was to concede an early goal - but that is just what happened with just eight minutes on the clock. Nicky Bailey was penalised for a foul on Chris Gunter and when Jordan Obita sent over the resulting free-kick from the right flank, captain Morrison was on hand to plant a firm header into the back of the net.
Adam Le Fondre was a couple of yards away from making it 2-0 shortly after with a fierce drive that flew over the bar from distance.
The Lions were forced to reshuffle their defensive pack just past the quarter-hour when Paul Connolly hobbled off gingerly after appearing to over-stretch clearing the ball and was replaced by Jack Smith.
As the half wore on Millwall slowly but surely recovered from conceding that early goal and, urged on by the travelling fans, started to ask questions of the Reading defence.
Martyn Woolford's stinging drive was superbly blocked by Alex Pearce, McDonald's shot bounced narrowly wide of the target and then Scott Malone's mazy run deserved a goal, only for his final delivery to be hacked clear by the boot of a home defender.
Trotter sent a glancing header from Martyn Waghorn's corner across the face of goal as The Lions kept the pressure on, but just could not find a way through a resilient Reading rearguard before the break.
It took a fine save by David Forde at full stretch to prevent the home side adding a second goal in injury-time, flinging himself across goal to keep out Pavel Pogrebnyak's effort.
The second-half started at a pace with chances at both ends. Reading thought they had added a second goal moments after the restart when Obita's cross picked out Adam Le Fondre and his close-range shot hit the inside of the post before the ball was gratefully gathered by Forde.
Play broke quickly up the other end and having come within a whisker of scoring, Reading were nearly pegged back on level terms when McDonald's low angled shot was arrowing towards the bottom left corner, only to be blocked by keeper Federici's outstretched boot.
McDonald went close on 49 minutes, this time sending a fizzing drive that was saved by the increasingly under-pressure Reading keeper.
Millwall thought they had equalised six minutes later when Danny Shittu slammed home from close range from Waghorn's inviting free-kick, flicked into his path by Paul Robinson, but his 'goal' was ruled out for the narrowest of offside decisions.
The introduction of Liam Feeney, and then Steve Morison added fresh impetus as The Lions continued to search for that elusive leveller, but it looked as if those hopes were going to be dashed five minutes from time when Abdou, already somewhat harshly booked for an innocuous looking challenge in the first-half, was shown a second yellow card for a tackle on Jobi McAnuff.
However The Lions once again dug in, determined to get some reward for their effort and endeavour. Morison was odds-on to score that all-important equaliser on 90 minutes when a fabulous run and cross by Feeney picked out the Welsh international striker, but he powered his header inches wide of the goal.
Millwall kept going, refusing to give up, and finally got their just rewards in the second minute of injury-time when Federici clattered McDonald as he broke into the area and referee Phillips had no hesitation in pointing to the spot.
Up stepped Trotter, who kept his cool to hit an unstoppable penalty high into the roof of the net to spark wild celebrations amongst the travelling fans and ensure that The Lions headed home with a thoroughly deserved point.
Reading: Federici, Gunter, Pearce, Baird, Pogrebnyak, Le Fondre (Robson-Kanu, 63mins), McCleary, Morrison, Bridge (Kelly, 82mins), Guthrie, Obita (McAnuff, 68mins). Subs: Kelly, McAnuff, Akpan, Gorkss, Robson-Kanu, Blackman, Taylor.
Millwall: Forde, Connolly (Smith, 15mins), Malone, Robinson, Shittu, Abdou, Bailey (Morison, 76mins), Waghorn, Trotter, Woolford (Feeney, 69mins), McDonald. Subs: Bywater, Feeney, Morison, Smith, Lowry, Derry, Easter.
Bookings: Bailey, Abdou, Malone, Shittu
Sending off: Abdou (85mins)