Cristiano Ronaldo s goal saw Portugal defeat the Czech Republic 1-0 on Thursday and book their place in the semi-finals of Euro 2012.
A cagey contest at the National Stadium, Warsaw, produced few real chances, with Portugal dominating possession but struggling to break down a stubborn Czech side.
Ronaldo was the chief threat throughout, sending an early bicycle kick wide of goal, before striking the post in each half.
It was the Real Madrid star who eventually broke the deadlock, stooping to meet Joao Moutinho s cross and heading beyond Petr Cech to register the winning goal with 11 minutes remaining.
Paulo Bento s team will face either France or arch-rivals Spain in the semi-finals.
The Czech Republic started well, and managed to claim the upper hand during the initial exchanges, as their control of possession restricted Portugal s enterprise.
Nevertheless, the first hint of an opening fell to Moutinho in the 13th minute, the Porto midfielder squeezing in a shot on the turn that was comfortably gathered by Cech.
It was a half-chance at best, and illustrative of the cagey beginning to the match, which saw both sides struggle to stamp their authority on proceedings.
Ronaldo forced Cech into action with a powerful drive after racing into the box, but the chance was quickly snuffed out by an offside call.
Nani and Miguel Veloso were then both booked within minutes of each other after a pair of thumping challenges on Vladimir Darida and David Limbersky respectively.
Slowly, Portugal began to make an improved contribution to the game, eschewing their long-ball approach for a more concerted offensive effort, with Ronaldo, as ever, at the heart of things.
The Real Madrid star went close with an audacious overhead kick that flashed just wide following a struggle by the Czech defence to clear a corner, before firing a 30-yard free-kick narrowly off target.
Portugal were handed a blow with 39 minutes gone when Helder Postiga limped off clutching his hamstring, with Hugo Almeida coming on in his stead.
The change did not faze Portugal too much however, who went closest to snatching the lead on the stroke of half-time.
Ronaldo collected Fabio Coentrao s cross perfectly on the turn, and drilled a low attempt that bounced agonizingly off the base of the post.
Ronaldo would come close once more a few minutes after the restart, with another long-range free kick brushing off the woodwork via a save by Cech.
Portugal were looking the superior side as the second half unfolded, with Raul Meireles sending two efforts over the bar, before Nani forced Cech to parry his low drive towards goal.
The Chelsea goalkeeper needed to be alert again on the hour mark to tip over a piledriver from Moutinho, with the Czech Republic struggling to get a sniff of the ball.
Meireles snatched at an opening from just inside the box, before slipping in Nani, whose deflected effort came close to looping into the top corner.
Just when it looked like there would be no way through for Portugal, up stepped Ronaldo to bounce a punishing header into the back of the net from a great cross by Moutinho.
Pereira nearly increased his team s advantage moments later with a well-taken drive, but Cech was equal to it and expertly tipped wide.
The Czech Republic s subdued second-half effort continued and they proved unable to rouse themselves in search of a way back into the match.
