Ajax remained on course for a domestic double after they knocked out defending KNVB Beker champions AZ Alkmaar with a 1-0 semi-final win.
The Amsterdammers will meet PEC Zwolle in the April 19 final after Lasse Schone's superbly-struck 48th-minute free-kick proved the difference after both teams has been reduced to 10 men.
AZ knocked Ajax out at this stage last year and should have taken control of this match when Joel Veltman saw red after giving away a 33rd-minute penalty.
But Ajax goalkeeper Kenneth Vermeer kept out striker Aron Johannsson's spot-kick. It was the second successive penalty the United States international has missed for AZ.
It proved costly too as AZ's numerical advantage was cancelled out when Mattias Johansson saw red shortly after half-time, and then a minute later Schone arced his 25-yard free-kick over the wall and beyond Esteban Alvarado's reach.