Brighton completed a stunning comeback in their FA Cup quarter-final tie against Millwall, capitalising on a goalkeeping howler to secure a late 2-2 draw before winning 5-4 on penalties.
After a goalless first half, Alex Pearce headed Millwall ahead in the 70th minute before Aiden O'Brien - on his 200th appearance for the club - slotted home eight minutes later and seemingly set the Lions on course for Wembley.
But the comeback was on for Brighton when Jurgen Locadia pulled one back in the 88th minute and, with 95 minutes on the clock, Millwall goalkeeper David Martin spilled a Solly March free-kick into his net to send the game into extra-time.
The added 30 minutes provided no further goals and, after Shane Ferguson was shown a straight red card in the 119th minute for a stamp, the game went to a penalty shootout.
Millwall initially held the advantage, thanks to Glenn Murray's miss, but Mahlon Romeo and Jake Cooper failed from the spot to hand Brighton a 5-4 shootout victory and send them into the semi-finals, where they will face Manchester City.
The hosts started the game well, having already taken the scalp of Everton at The Den in the fourth round. Jed Wallace and Lee Gregory had shots before a Cooper header tested Mat Ryan for the first time, but the Brighton goalkeeper collected his weak header.
The best chance of the half came for Millwall in the 28th minute as Gregory collected a Wallace nod down and, with his back to goal, tried to scoop the ball over the top on the turn but sent it onto the roof of the net.
Brighton could then have been awarded a penalty just before the break. Shane Duffy nodded wide from a Anthony Knockaert corner, but it appeared that Cooper had a hold of Duffy's arm in the build-up.
However, the Video Assistant Referee was not in use as the game was not being played at a Premier League stadium, so the decision was not able to be reviewed.
As the second half began, the heavens opened in south London and it took a while for the game to rediscover its rhythm amid the hail. In the 57th minute, Beram Kayal powered the ball towards goal from the top of the area, but Martin made a smart save before Gregory slid Wallace through into the area, forcing Ryan out to make a big stop.
Millwall then began to take control of the game with Ryan making two good saves from Shaun Williams and Gregory, and they made the breakthrough in the 70th minute. Williams swung a corner towards the back post and Pearce was there to meet it, powering his header through a packed six yard box and into the back of the net.
Eight minutes later, and Millwall added their second. Wallace burst down the right flank, beating his marker, before cutting into the box. He then played the ball back for O'Brien, who turned the ball home.
But Brighton came roaring back into the tie as the clock ticked down with Locadia firing home from eight yards after fine work on the wing by March in the 88th minute, before March unexpectedly scored himself in the fifth minute of injury time.
His free-kick - which appeared to be sailing wide - slipped through the fingers of goalkeeper Martin and into the net, sending the game into extra-time.
Millwall had the only real chances of note in the first 15 minutes, as Ryan saved a low strike from James Meredith before Romeo sent the rebound blazing over the crossbar. Brighton looked the more likely to score in the second added period, Locadia flashing a shot wide on the angle before Dale Stephens' drive went straight into the hands of Martin.
The hosts went down to 10 men with just a minute of the extra period to be played as Ferguson - an almost-certain penalty taker for the Lions - was shown a straight red card. After a foul on Lewis Dunk, he then stood on the back of the Brighton defender's leg and was sent off by referee Chris Kavanagh.
After a goalless 30 minutes of extra-time, the game went to penalties. Murray pinged the opening penalty onto the crossbar, before Romeo saw his effort saved by Ryan. With the others scored, it went to sudden death and was down to Cooper to keep Millwall in the game, but he fired his penalty high to spark Brighton celebrations.
Opta stats
- Brighton have qualified for the FA Cup semi-final for just the second time in their history - previously doing so in 1983 when they finished as runners-up.
- Brighton are just the third side to reach the FA Cup semi-final stage after winning on penalties after Sheffield United (1993 and 1998) and Arsenal (1998).
- Millwall have lost seven of their last eight penalty shootouts, losing their last two in the FA Cup.
- Millwall's first seven goals in the FA Cup this season came from set-pieces (free-kick x4, corner x3), with Aidan O'Brien's goal the first from open play.
Man of the match - Solly March
March came on as a substitute in the 67th minute, but what an impact he had. He set up the first and scored the second of Brighton's late goals, and was the man trying to create something for the visitors in the added period when others around him were tiring.
He also stepped up to take a penalty under plenty of pressure, and scored, thoroughly deserving the title of man of the match.
What's next?
Both sides will now have a weekend's break due to the upcoming internationals, with Millwall travelling to Leeds in the Sky Bet Championship on Saturday, March 30 while Brighton will host Southampton on the same day.