Ricardo Quaresma was Portugal's hero for the second successive game as he capitalised on Jakub Blaszczykowski's missed spot-kick to seal a 5-3 penalty shootout win over Poland in the UEFA Euro 2016 quarter-finals.
Substitute Quaresma scored the only goal as Portugal, which has reached the semi-finals without winning a game in 90 minutes, defeated Croatia in the Round of 16.
The winger rifled his spot-kick high into the goal after Rui Patricio had got down low to his left to push aside Blaszczykowski's effort at the Stade Velodrome as the match had finished 1-1 after extra time in Marseille.
It could easily have been a different story for Poland, which beat Switzerland on penalties in the previous, as Robert Lewandowski, much maligned for a series of poor performances throughout the tournament, netted the second-quickest goal in Euro championship history to end a 645-minute wait for a goal in the tournament.
Portugal levelled just after the half-hour, though, as Renato Sanches — man of the match off the bench versus Croatia — marked his first international start by becoming the youngest scorer in a Euro championship knockout match.
Portugal was left celebrating after the shootout, the miss particularly harsh on Blaszczykowski, who scored twice earlier in the competition and has been so influential in Poland's best showing at a European championship.
Wales or Belgium now awaits Portugal in the last four.
Both teams played 120 minutes in their Round of 16 ties, but Poland showed no signs of weariness early on and stormed ahead after 100 seconds.
Cedric misjudged a looping pass and Kamil Grosicki raced down the left before centring for Lewandowski, who clinically side-footed into the left corner from 10 yards.
Cristiano Ronaldo and Nani were largely isolated by Poland's stern defence early on, but the momentum slowly shifted Portugal's way, the former flashing a shot at Lukasz Fabianski from the edge of the box before seeing penalty claims waved away after being bundled to the ground by Michal Pazdan.
The leveller came in the 33rd minute. Nani's clever flick set up Sanches and his 25-yard left-foot effort took a slight deflection before nestling in the right of the goal past a despairing Fabianski.
There was little to split the teams at the start of the second half, but Ronaldo will feel he should have done better after being slipped in on the left of the area and shooting straight into the side-netting.
Ronaldo then fluffed his lines from eight yards with an air shot after finding space to meet Nani's low ball, before Cedric flashed a 25-yard effort past the left-hand post.
Portugal almost got lucky when Artur Jedrzejczyk's attempted clearance came close to finding Fabianski's bottom left corner, while the luckless Ronaldo failed to make contact with Joao Moutinho's sublime ball over the top.
Neither team was able to make the breakthrough in regulation time, though, and there were few talking points in a drab extra-time — the match pausing briefly owing to a pitch invader.
That meant penalties were required to settle the affair with Ronaldo and Lewandowski setting the tone for a fine shootout with excellent penalties.
But it was Blaszczykowski that felt the spot-kick pain with the eighth effort, Patricio pushing away strongly with a big left hand to set the stage for Quaresma to emphatically hammer home the winner.