A first-half Anthony Gordon strike proved to be the difference between the two sides, as the Young Lions withstood relentless second-half pressure from Portugal to book a semi-final date with Israel on Wednesday.
After making wholesale changes for his side's dead rubber against Germany in their final group game, Lee Carsley reverted to his strongest XI for the showdown with the 2021 silver medallists, and his refreshed troops exploded out of the blocks.
Liverpool's Curtis Jones sent an effort just wide of the mark from the edge of the area with four minutes gone, but after weathering an early storm, Portugal began to make a few inroads.
James Trafford was called into action for the first time in the 12th minute, producing a strong reaction save down low from Pedro Neto, who managed to test the England number one from a tight angle.
However, England's usual suspects were up to their old tricks, and Carsley's strike partnership combined for a deserved opening goal with 34 minutes on the clock.
A slick England attack saw Noni Madueke feed Morgan Gibbs-White on the right-hand side of the box, and the Nottingham Forest man cut back first time for Gordon, who was in acres of space to crash home a side-footed strike into the centre of the goal from 12 yards.
Portugal tried to respond to England's opener before the break, but their efforts were futile; Pedro Neto blazed a free kick over the bar, before Tiago Dantas was denied brilliantly by Taylor Harwood-Bellis just before the whistle blew.
Rui Jorge must have had some choice words for his players during the interval, though, as Portugal were a side reborn following the restart, and substitute Paulo Bernardo should have restored parity with 59 minutes gone.
Once again, Neto was the instigator as he whipped in a cross from the left-hand side, but Bernardo could only head wide of Trafford's far post from a promising position.
England continued to face a bombardment of Portugal attacks, and to make matters worse for Carsley, Aston Villa midfielder Jacob Ramsey was forcibly taken off with a foot problem in the 67th minute; two-goal Arsenal man Emile Smith Rowe replaced him.
Portugal had made a change of their own a few minutes prior as Henrique Araujo replaced Fabio Silva, and the former managed to get a shot away in the 69th minute, but this time it was Levi Colwill's turn to get his body in the way.
Jorge's side screamed for a penalty only a minute later as a tangle between Araujo and Harwood-Bellis saw both men go to ground, but referee Rade Obrenovic waved away the appeals, and the VAR room saw no need to intervene.
Araujo continued to torment the England backline, though, and the Benfica attacker crashed a near-post header against the crossbar in the 73rd minute, before Nuno Tavares tried his luck with a header into the ground nine minutes later, which was meat and drink for Trafford.
It took 42 minutes of the second half for England to register another attempt, as Gordon failed to test Celton Biai from long range, but the Young Lions survived six minutes of injury time to advance to the final four for the first time since 2017.