DONETSK - Cesc Fabregas struck the winning spot kick as holders Spain beat Portugal 4-2 on penalties after their Euro 2012 semi-final ended goalless after extra time on Wednesday.

Spain keeper Iker Casillas saved Joao Moutinho's opening penalty then Bruno Alves hit the bar to eventually open the door for substitute Fabregas, who scored via the post.

Portugal's Nelson Oliveira (R) heads the ball next to Spain's Alvaro Arbeloa during their Euro 2012 semi-final soccer match at Donbass Arena in Donetsk, June 27, 2012. [Photo/Agencies]

After a lively first half when Portugal took the game to their neighbours, it got cagier with fewer chances as Cristiano Ronaldo lashed two dipping free kicks just over the bar and sent another flying over in the last minutes after a counter-attack.

Spain's Alvaro Arbeloa swept a half-volley over the bar in the ninth minute and remarkably that proved to be Spain's best chance of a disjointed performance until Andres Iniesta forced Rui Patricio into his first serious save just before halftime in extra time when they finally injected some pace and took control.

Germany play Italy in Warsaw on Thursday in the second semi-final with the final in Kiev on Sunday.