After being under the cosh for much of the opening period - with the woodwork coming to their rescue on three occasions - goals from Dominic Solanke and Patrick Roberts fired England into Wednesday’s final.
Freddie Woodman returned between the sticks as Tafari Moore and Taylor Moore lined up in the back four in place of Mandela Egbo and Dael Fry.
Portugal 0-2 England
UEFA U17 European Championship
Sunday 18 May
Ta' Qali National Stadium, Malta
Lewis Cook replaced Joshua Onomah in midfield as Dominic Solanke, Patrick Roberts and Adam Armstrong all rejoined the starting eleven to spearhead the attack.
With the wind behind them, England started strongly, winning four corners inside the opening two minutes - but deliveries from Armstrong and Roberts mounted to nothing.
The Young Lions were controlling possession, but Portugal always looked dangerous on the counter and it was they who created the first clear chances of the game.
Firstly, Joe Gomez was caught as he attempted to bring the ball out of defence as Goncalo Rodrigues dispossessed him 25 yards out on fifteen minutes. He played it to Diogo Goncalo on the right, who squared it back to Rodrigues to strike from ten yards, but Woodman saved well with his legs.
Moments later the pressure began to mount on the England defence as the woodwork came to their rescue twice. Goncalo, who scored against England in a 2-2 draw at the Algarve Tournament in February, saw his strike from an acute angle deflect off the upright, before Ruben Neves’ thirty-yard thunderbolt strike cannoned back off the crossbar and away to safety.
The Young Lions were struggling to mount an attack, and their goal threat was dented further on 35 minutes as Adam Amrstrong, the scorer of nine goals throughout this European campaign, limped off to be replaced by Josh Onomah as Dominic Solanke was moved to the central striking position.
Things almost got worse as the half-time whistle neared, but thankfully for England the woodwork came to their rescue again. The impressive Goncalves hit an inswinging shot from the left-hand side of the area that left Woodman stranded, but fortunately the Newcastle United goalkeeper was alert to catch the ball as it rebounded of the upright and into his arms.
No changes were made by either side at the half-time interval – but it was England who started on the front foot as Onomah fired over from ten yards inside three minutes of the restart.
The Lions began to press and they had the Portuguese on the back foot. They looked a transformed team from that of the first-half. The battling spirit associated with the team throughout the qualification campaign was now back in full flow as they started to dominate their opponents and they deservedly took the lead on 52 minutes.
Taylor Moore picked up the ball and embarked on a driving run across the half-way before hitting an inch-perfect ball into the path of Solanke. The Chelsea forward evaded the challenge of a defender to calmly lift the ball over the onrushing Duarte.
England now had their tails up, but they were almost caught on the counter when Goncalves headed wide from Buta’s cross on 60 minutes.
A second nearly arrived for Peacock’s men seven minutes later when a scramble in box involving Onomah and Solanke saw the ball roll goalwards before a defender hooked it away on the line.
They did not have long to wait, though, and with six minutes remaining Patrick Roberts doubled the Young Lions' lead.
The Fulham youngster, who had a quiet game by his standards, picked up the ball on out on the right and ran into the box. He beat three defenders before finishing left-footed, albeit with a slight deflection. Wild celebrations ensued and the Young Lions had booked their place in a third European U17 Championship Final.
England will face Holland in Wednesday's Final at the National Stadium after their 5-0 victory over Scotland in the day's second Semi-Final.
12 Fabio Duarte; 2 Hugo Santos, 3 Ruben Dias, 13 Francisco Ferreira, 5 Yuri Ribeiro; 6 Ruben Neves (c), 7 Diego Goncalves, 8 Goncalo Rodrigues; 10 Renato Sanches, 9 Alexandre Silva, 15 Joao Carvallho.
18 Buta for Rodrigues (55), 14 Pedro Empis for Ribeiro (75), 17 Pedro Delgado for Carvallho (76).
Substitutes not used
1 Pedro Silva, 4 Pedro Rodrigues, 11 Luis Mata, 16 Diogo Izata
Bookings: Silva (29)
Head coach: Emilio Manuel Delgado Peixe
1 Fred Woodman (Newcastle United); 2 Jonjoe Kenny (Everton), 5 Joe Gomez (Charlton Athletic), 15 Taylor Moore (RC Lens), 3 Tafari Moore (Arsenal); 4 Ryan Ledson (C; Everton), 14 Lewis Cook (Leeds United); 18 Patrick Roberts (Fulham), 11 Isaiah Brown (Chelsea), 10 Dominic Solanke (Chelsea); 9 Adam Armstrong (Newcastle United).
8 Joshua Onomah (Tottenham Hotspur) for Armstrong 35, 12 Mandela Egbo (Crystal Palace) for Moore (72), 16 Callum Cooke (Middlesbrough) for Roberts (75)
Goals: Solanke (55), Roberts (74).
Substitutes not used
13 Sam Howes (West Ham United), 6 Dael Fry (Middlesbrough), 7 Demetri Mitchell (Manchester United), 17 Josh Sims (Southampton)
Bookings: Cook (68), Egbo (80+3).
Head coach: John Peacock
Referee: Alexander Harker (Austria)