Millwall's Emirates FA Cup campaign ended in heartbreak on Sunday afternoon as Brighton & Hove Albion won 5-4 on penalties following a 2-2 draw after extra time.
In an eventful game, Alex Pearce and Aiden O'Brien's goals looked to have done the damage in nine second-half minutes, but Jurgen Locadia halved the deficit late on before Solly March's free-kick in the 95th minute meant extra-time.
With no goals in the 30-minute period, nine out of 12 spot-kicks were scored - five for Brighton, sending them to a Wembley Semi-Final.
Neil Harris made two changes for Sunday's game - both enforced - as Shaun Williams and O'Brien, on his 200th Lions appearance, replaced the Cup-tied Ben Thompson and Ben Marshall. Conor McLaughlin and Jiri Skalak, meanwhile, stepped up the bench, whilst Ben Amos took the place of Jordan Archer, who was ill.
In front of a packed-out Den, The Lions made the early running and fashioned a half-chance, but the ball was cleared to safety. Millwall were seeing a lot of the ball, and with three minutes on the clock Mahlon Romeo broke into the box, with the play eventually landing at the feet of Jed Wallace - he was to curl an effort wide, however.
Lee Gregory's skill then saw him go past two Brighton players as The Lions' fantastic and high-tempo start continued, but his half-volley bounced off O'Brien and behind. After Shane Ferguson carried the ball down the line and got the Den crowd on its feet, Jed Wallace's free-kick was whipped in to the head of Jake Cooper, but he nodded into the arms of Mat Ryan.
Brighton's first opportunity came on 15 minutes, but after Anthony Knockaert burst into the penalty area, Ryan Tunnicliffe's booming kick to safety prevented David Martin from being tested.
The Den's atmosphere was getting louder by the minute, and on 26 minutes the roof could have been lifted off with a Millwall goal, but Romeo took one touch too many and the ball was cleared. At the other end, Cooper's clearance found its way to the boot of Beram Kayal, but Martin was well placed to save. Gregory then turned and shot on to the roof of the net as an eventful first-half continued.
Just 11 minutes before the break, Knockaert once again swung over a cross, this time to the head of Kayal, but the attempt as weak and claimed by Martin. Knockaert tried his luck from distance but found the lower tier, whilst Shane Duffy headed wide as the half came to a conclusion.
The second-half was just three minutes old when The Lions could have taken the lead, but after Duffy and Ryan got themselves in a muddle at the back, Gregory was just unable to out-muscle the stopper and roll into an empty net.
With 57 minutes on the clock Kayal opened up his body and curled an attempt towards goal, but Martin parried away, with The Lions' defence stopping any rebound coming the goalkeeper's way. Jed Wallace wa sent through a minute later, but Ryan stood tall and saved.
Williams, captaining the side for the day, then had a chance to break the deadlock on 64 minutes, but following a neat passing move, the Irishman fired straight at Ryan. Ryan Leonard then won possession and slipped in Gregory, but the stopper was out quickly to smother any attempt on goal, knocking the ball behind for a corner - one which Cooper headed wide.
With 20 minutes remaining, The Den erupted - the goal that had escaped the afternoon up to press came, as Pearce powered in a header from a corner for his first goal for the club.
Chris Hughton responded by opting for a double change, with Bernardo heading wide on the edge of the six-yard box as The Seagulls looked to equalise.
With 11 minutes remaining, the lead was doubled. Jed Wallace skipped past two and supplied a low cross into the box for O'Brien, who had the simplest of tasks in tapping home.
Two minutes from time, Brighton substitute Locadia rifled home from close range to reduce the arrears, whilst in four minutes of stoppage-time, the unmarked Jose Izquierdo shot straight at Martin.
It wasn't over there, however, as March's free-kick evaded everyone and dipped into the net in the fifth minute of injury-time.
With attacking threats Jed Wallace and Gregory now off the field, Millwall had to negotiate extra-time with one recognised forward - Steve Morison - on the pitch, and in the 95th minute they were presented with a golden chance as James Meredith's shot looped up into the path of Romeo; he, however, blazed high, wide and not so handsome.
After 109 minutes of football the ball was at the feet of Locadia inside the six-yard box, but the striker could not control properly, with Leonard able to clear to safety. Locadia then fizzed a shot over the bar on 117 minutes, whilst Dale Stephens found the arms of Martin a minute later.
As the clock moved towards the 120-minute mark, Ferguson was shown a straight red card for apparently lashing out at Lewis Dunk.
And so to penalties. Glenn Murray smacked the crossbar to open up, before Williams slotted low to the right of Ryan to put The Lions ahead. Locadia then made no mistake, before Tunnicliffe eased his spot-kick home. March thumped home, with Leonard returning serve. Davy Propper kept the shoot-out going, but Romeo's penalty was saved by Ryan. Stephens then scored, as did Morison, as did Dunk, but Cooper fired over the bar to end the contest and The Lions' heroic run.
Millwall: Martin, Cooper, Williams, J. Wallace (Hutchinson 90+3'), Gregory (Morison 90'), Ferguson, Romeo, Pearce, Tunnicliffe, O'Brien (Meredith 85'), Leonard. Subs not used: Amos, McLaughlin, Elliott, Skalak.
Scorer: Pearce 70', O'Brien 79'
Penalties: Williams (scored), Tunnicliffe (scored), Leonard (scored), Romeo (saved), Morison (scored), Cooper (missed).
Sent Off: Ferguson
Brighton & Hove Albion: Ryan, Duffy, Dunk, Stephens, Kayal (Locadia 73'), Knockaert (Izquierdo 73'), Jahanbaksh (March 67'), Murray, Montoya, Propper, Bernardo. Subs not used: Button, Bruno, Bong, Burn.
Scorer: Locadia 88', March 90+5'
Penalties: Murray (missed), Locadia (scored), March (scored), Propper (scored), Stephens (scored), Dunk (scored).
Booking: Bernardo, Montoya
Referee: Christopher Kavanagh
Attendance: 17,137 (2,338)