Danny Welbeck came off the bench to fire Brighton & Hove Albion into the FA Cup quarter-finals against Newcastle United.
Welbeck scored deep into extra time to secure a dramatic 2-1 victory after both teams were reduced to 10 men.
Newcastle's Alexander Isak and Brighton's Yankubah Minteh scored in the first half before Welbeck struck the winner in the 114th minute with an exquisite finish from a tight angle.
"It was a very emotional game," Brighton manager Fabian Hurzeler told the BBC. "Lots of ups and downs. The key was we stayed together, we stayed calm, we tried to find solutions."
There was more bad news for Newcastle as Anthony Gordon's League Cup final dream was shattered by a late red card.
Gordon was sent off for violent conduct with six minutes of a chaotic tie remaining - Tariq Lamptey later suffered the same fate after collecting a second yellow card - and faces a three-match ban which will cost him his place in the team for the clash with Liverpool at Wembley on March 16.
Brighton have never lifted the FA Cup and last reached the final in 1983 when they lost in a replay against Manchester United.
It was a bitter blow for Newcastle, who haven't won a domestic trophy since landing the 1955 FA Cup, while their last major trophy was the 1969 Inter-Cities Fairs Cup.
Newcastle made a vibrant start as Harvey Barnes lofted a pin-point cross to the far post, where Isak blazed over from close-range after his initial effort was blocked by Adam Webster.
Isak tested Brighton keeper Bart Verbruggen with a long-range drive before Newcastle took the lead in the 22nd minute.
Minteh conceded a penalty with his rash challenge on Tino Livramento. Isak confidently lashed the spot-kick into the top corner.
It was Isak's 22nd goal in all competitions this season and the Sweden striker had the ball in the net again with a ferocious blast, only for an offside flag to curtail his celebrations.
Newcastle looked in command when Gordon cut inside for a curler that Verbruggen saved at full stretch.
But Brighton snatched an equaliser against the run of play in the 44th minute.
Joao Pedro's superb pass picked out Minteh inside the area and the Gambian's shot took a deflection as it flashed past Newcastle keeper Martin Dubravka.
It was a sweet moment for Minteh, who joined Brighton from Newcastle last year in a £30 million deal.
Gordon saw red with seven minutes left in normal time, the England star lashing out at Van Hecke as they challenged for the ball after play was stopped for offside against Isak.
Lamptey followed Gordon down the tunnel in stoppage-time after the Brighton defender's rash foul on Jacob Murphy.
Fabian Schar thought he had volleyed Newcastle's winner in stoppage-time, but the defender was ruled offside after a VAR check.
Brighton came on strong in extra time. Dubravka made a fine stop to keep out Diego Gomez's rocket from the edge of the area.
Newcastle were under pressure and Welbeck won it for the Seagulls in the 114th minute, racing onto Solly March's defence-splitting pass and clipping his shot over Dubravka.
