Atletico Madrid have been left with it all to do in the Copa del Rey quarter-finals as a late Miguel Angel Moya own goal was followed by a Joaquin Correa winner in Sevilla's shock 2-1 triumph at the Wanda Metropolitano.
Diego Costa's third goal in four games since re-joining Atletico arrived 17 minutes from time and appeared to have secured the hosts a slender first-leg victory, but a fortuitous Moya own goal after a Jesus Navas cross made things interesting.
Then, with only two minutes left, Joaquin Correa punished Atletico on the break to secure a fine result.
There was little indication of the two teams' contrasting recent fortunes during the first half, as Sevilla - who had won just two of their previous eight in all competitions - gave as good as they got in an entertaining encounter.
Joaquin Correa, Pablo Sarabia and Sergio Escudero all went desperately close for the visitors, while Costa twice troubled Sergio Rico in the Sevilla goal.
Former Chelsea star Costa had seemingly ended Sevilla's resistance when he scored fairly late in the day with an emphatic left-footed strike.
1 - Sevilla are the first Spanish team to win against Atletico at Wanda Metropolitano in all competitions. Historic. pic.twitter.com/vwAEaL9vTB
-- OptaJose (@OptaJose) January 17, 2018
But Sevilla rallied brilliantly to somehow leave the Wanda with a result that means they will take a surprise lead to the typically raucous Ramon Sanchez Pizjuan for next Tuesday's second leg.
Despite seeing much less of the ball than Atletico, Sevilla arguably looked the more threatening going forward at times in the first half.
Franco Vazquez fired just wide from 18 yards early on, before Sarabia hit a half-volley on the spin from a similar distance which agonisingly missed the top-right corner.
Atletico and Costa soon woke up, however.
The Spain international saw a headed goal disallowed 13 minutes in after tussling with Gabriel Mercado at a corner and forced Sevilla goalkeeper Rico to brilliantly turn another header around the post soon after.
Sevilla remained a potent threat on the break and should have scored just before the half-hour mark, but Joaquin Correa shot straight at Moya when through on goal.
The end-to-end nature of proceedings continued right until the break - Costa again testing Rico from a tight angle after a swift counter, before Moya tipped Escudero's spectacular long-range effort over.
Vitolo - who departed Sevilla in a contentious transfer in July - was so ineffective against his former employers that Diego Simeone opted to hook him for Angel Correa at the break, and the substitute caused trouble almost straight away with his crossing.
His first delivery across the face of goal was nearly turned in by Costa, before Clement Lenglet headed the forward's second cross onto his own post.
There was to be no denying Costa in the 73rd minute, however, as the lively striker lashed a left-footed drive into the bottom-right corner after Sevilla failed to clear a free-kick.
But the visitors were by no means out of it.
Substitute Navas played a pivotal - albeit lucky - role in the equaliser, as his right-wing cross took a deflection off Lucas Hernandez and found its way in via the glove of Moya.
And Joaquin Correa then secured Sevilla's first win at Atletico in any competition since September 2008, racing onto Wissam Ben Yedder's pass and prodding cleverly past the helpless Moya to set up a tantalising second leg.