Given that March’s shock 2-0 loss to Slovenia was Roberto Martinez’s first defeat on his 12th game in charge, it was never going to be an easy start for Portugal, and a markedly solid Slovenia rearguard initially proved extremely difficult to break down.
Half chances flashed the way of Rafael Leao and Cristiano Ronaldo, but neither man was able to connect with excellent crosses and notch the opener.
Having taken more shots than anyone else in this tournament without actually scoring, Ronaldo was utterly fixated on breaking his duck, and another squandered header was followed by a pair of free kicks thundered into the stands.
It was instead Slovenia who had the best of the first half’s final minutes, with star forward Benjamin Sesko firing down the throat of Diogo Costa.
They were almost stunned on the stroke of half-time though, by a low Joao Palhinha drive which brushed against the base of the post.
Beating Jan Oblak – whom Ronaldo had failed to find a way past in their previous five meetings – was proving a difficult proposition for Portugal’s talismanic number seven, and even when he did rocket a set piece on target the towering Slovene was right behind it.
The excitement began to peter out as both sides prepared for extra time, although Šeško put wide on the counter before Ronaldo shot straight at Oblak with his best opportunity of the match so far.
The Seleção had simply not created enough in normal time, but they were granted by far their best opportunity when Vanja Drkusic felled Diogo Jota in the area and referee Daniele Orsato pointed to the spot.
Ronaldo was the man to step up once again, but he was denied by a sensational stop by Oblak, who pushed the penalty onto the post and out.
With penalties looking almost certain, Pepe stumbled to put Šeško through on goal, but a vital save by Diogo Costa denied him what would have been a famous winner.
Agonisingly, Slovenia missed each of their first three penalty kicks, while Portugal scored all of theirs, including Bernardo Silva’s winner.
It was considerably more difficult than expected for Portugal in the end, but they nevertheless advanced to a blockbuster quarter-final against France, going one better than three years ago when they were beaten by Martínez’s Belgium.
Regardless of the result, there will certainly still be celebrations in the streets of Ljubljana tonight, heralding a team which has brought unprecedented success to the little state in the crook of the Adriatic.