Lukas Hradecky proved the hero as Eintracht Frankfurt reached the DFB-Pokal final for the first time in 11 years with a 7-6 penalty shoot-out win over Borussia Monchengladbach.
Four-time winners Frankfurt had led through Taleb Tawatha until Jonas Hofmann's equaliser, but, following a nervy period of extra-time which ended with the scores locked at 1-1, Hradecky decisively denied Andreas Christensen and Djibril Sow from the spot before former Gladbach striker Branimir Hrgota netted the winner.
Although the two sides played out a pair of goalless draws in their Bundesliga meetings this season, Gladbach's back-line has been leaky of late - conceding 10 goals in the prior three league games - and Frankfurt quickly exploited their generous defending.
Tawatha's opener arrived with quarter of an hour on the clock, but the visitors' momentum slowed after scoring and Hofmann fired a leveller on the stroke of half-time.
A stoppage for an apparently serious shoulder injury to Frankfurt substitute Marius Wolf broke up a tame second period as the evenly matched teams headed for penalties.
Frankfurt had twice relied on penalties to reach this stage and Hradecky's heroics here set up a meeting with Bayern Munich or Borussia Dortmund - who face each other in the other semi-final on Wednesday - at Berlin's Olympiastadion on May 27.
Frankfurt made a fine start as Marco Fabian dragged a loose ball wide after Yann Sommer had dived at Hrgota's feet and Timothy Chandler's incisive pass teed up Ante Rebic to shoot off target, the visitors' early pressure bearing fruit with a goal after 15 minutes.
Chandler was again the creator, his cross from deep reaching the left side of the box and Tawatha, who rifled a superb strike into the top corner that Sommer could only tip onto the post on its way in.
Gladbach finally mustered a notable effort in response as Hradecky fumbled Tobias Strobl's long-range drive, but Frankfurt were soon back on the attack and Rebic similarly tested Sommer.
With a raucous crowd urging improvement from the struggling home side, Ibrahima Traore's deflected shot worked Hradecky again and the goalkeeper, stranded outside his area, was then fortunate to see Hofmann lift a finish wide from Sommer's arrowing long ball.
And, in first-half stoppage time, Gladbach hit back. Traore crossed from the left, Andre Hahn flicked the ball on and Hofmann steered a volley past Hradecky.
Frankfurt regrouped and Fabian shot straight at Sommer, but clear chances were few and far between after the interval.
Wolf was stretchered off just 13 minutes after replacing Omar Mascarell and, although Lars Stindl's low strike drew another save from Hradecky, a scrappy match was destined for extra-time.
However, both sides continued to toil in front of goal - Laszlo Benes curling over the top and Nico Elvedi shooting meekly on target for Gladbach - and only penalties could separate them after a third stalemate of the season.
The two teams each tucked away their first five spot-kicks in some style and that theme continued into sudden death, before, with the score at 6-6, Hradecky and Sommer denied Christensen and Guillermo Varela, respectively.
But Hradecky then saved again from Sow, allowing Hrgota to net the winner against his former club and clinch a final berth.
