Cristiano Ronaldo was Portugal's hero once more as he came up with the only goal of the game to send his team into the Euro 2012 semi-finals at the expense of the Czech Republic.
It was looking as though it might be a frustrating evening in Warsaw for Ronaldo and co. as Paulo Bento's side had a succession of near misses. But the deserved breakthrough finally came 11 minutes from time as Ronaldo got his third goal in two games with a powerful header from Joao Moutinho's cross.
The Czech Republic defied their tag of underdogs early on as they valiantly took the game to their opponents. Once Portugal got going midway through the first period, though, it became increasingly one-way traffic, with the Czechs having goalkeeper Petr Cech and the woodwork to thank for the narrowness of the score line.
The Czechs' bright start was in no small part down to some impressive play from Vladimir Dorida. Making his first start for his country, in place of the injured Tomas Rosicky, the midfielder linked up well with the likes of Petr Jiracek and Vaclav Pilar going forward.
Dorida was the creator as the Michal Bilek's side came close to taking a surprise lead. The 21-year-old burst into space down the right and produced a teasing low ball in, but Milan Baros was just unable to get his toes on the ball to divert it goalward.
But as the game went on Portugal managed to find some momentum and by the half were unlucky not to be ahead. Unsurprisingly it was Ronaldo's increased involvement that was doing the damage to the Czechs' rear guard. The Real Madrid man had fans on his feet as he tried an ambitious overhead kick at the back post that whizzed wide of the target.
With Eusebio and Luis Figo watching on from the stands, Ronaldo produced a sublime bit of skill for which the Portuguese legends would have been proud as he failed by mere inches to give his side the lead in first-half injury time.
Raul Meireles' curled ball over the top of Michael Kadlec was chested down by Ronaldo then flicked away from the defender and into the forward's path, before drilling a shot that smacked off the near post.
They may not have scored, but Portugal had firmly gained the initiative in the contest. The midfield battle had battle had swung decisively, with Moutinho and Meireles both excelling. And, despite an injury suffered to Helder Postiga, the Selecco das Quinas continued to pepper the Czech goal after the restart.
Meireles produced an inviting cross for substitute Hugo Almeida to attack at the near post, but the striker ballooned his header over from six yards.
The Czechs were struggling to survive and their woodwork was shaking for a second time courtesy of an increasingly anguished-looking Ronaldo. From 25 yards, he fired a free-kick with trademark dip and swerve that struck the foot of Cech's post.
That effort gave Portugal the ignominious record of having hit the frame of the goal more times than any other country in a European Championships, with six.
The frustration was only building for Portugal's talisman as, under pressure from Theodor Gebre Selassie, Ronaldo failed to capitalize on Meireles' through ball, striking his effort high and wide.
When Portugal did hit the target, Cech was proving to be a more than able last line of defense, denying both Nani and Moutinho with first-class saves. Kadlec too defied the opposition with a fine block to deflect Nani's shot inches wide of the target.
When the Czechs' defenses were breached the assistant's offside flag came to the rescue as Hugo Almeida put a diving header beyond Cech from Nani's fine cross.
But just as it looked like Portugal might be taken to extra time, the long-awaited goal finally arrived. Moutinho burst past Jaroslav Plasil on the edge of the box and delivered a cross of real quality from the right that traveled over the head of Hugo Almeida and allowed a determined Ronaldo to beat Gebre Selassie to the ball before thundering a header down into the ground and past the diving Cech.
Though Cech tried to produce some late drama as he came up for a corner, the Czechs' attacking threat had faded badly after their encouraging opening. Portugal held out with comfort to take their rightful place in the last four where a match with either Iberian neighbors Spain, or France awaits.