Joe Allen played the full 90 minutes in midfielder but could not prevent his country from slipping to a devastating defeat, with quickfire second-half goals from Cristiano Ronaldo and Nani enough for the Portuguese to secure victory and progression to the final.
The game was arguably Allen's most disappointing performance of the tournament, following a number of excellent displays as one of the Dragons' key performers.
Booked inside just seven minutes, the 25-year-old was unable to snap into tackles with the intensity he normally would, although he was typically tidy and efficient in possession for much of the night.
Although Chris Coleman's team performed disappointingly against Portugal, they were one of the tournament's best performers on the whole - exceeding all expectations to reach the last four in their first major finals since 1958.
The Welsh team captured the imagination of a nation, topping Group B over home nations rivals England, before edging past Northern Ireland and thrashing Belgium to reach this stage.
Their slogan, 'Stronger Together', embodied their approach on the pitch as a cohesive team more than the sum of its parts helped to down a number of opponents who would have been backed to beat them before the tournament began.
Reds' Welsh duo can be proud of their efforts despite disappointing exit
But unfortunately, they could not become the first British nation to reach the final of a major international tournament in 50 years - since England's 1966 World Cup triumph on home soil - after an underwhelming showing in the semis.
Danny Ward, who did not make an appearance after starting Wales' opening game of the tournament in the group stages, was once again an unused substitute in Lyon.
The result was Portugal's first win inside 90 minutes at the tournament after drawing all three of their group games and requiring extra-time and penalties in their previous two knockout phase clashes.
Unless any transfer deals are completed between now and then, Allen and Ward will be expected to join up with the Liverpool squad three weeks on from now - likely July 28, the date of their first pre-season friendly in the United States.
The Reds travel to America a week earlier as part of a programme which sees them face three fixtures across the pond, meaning Allen and Ward could remain on Merseyside rather than travel to the US to join up with their teammates.
But by then, Allen could well have left the Reds. They have already rejected an £8 million bid for Swansea City, while Europa League holders Sevilla have publicly declared their interest in the midfielder.
Frustrated at a lack of game time under Jürgen Klopp last season, despite emerging as one of the side's best performing players in the second half of the campaign, Allen could leave as he enters his final year of his contract on Merseyside.
Liverpool are reportedly holding out for around £14 million for the in-form midfielder, insisting that they will not be held to ransom despite Allen having just 12 months remaining on his deal.
Goalkeeper Ward, meanwhile, is potentially in line for a loan to Championship side Huddersfield Town - managed by David Wagner who was the coach of Borussia Dortmund II for four years while Klopp was in charge of Dortmund's first-team.
The result means Liverpool now have only one representative left on international duty at the Euros, having started with a joint-high number of 12 - all of whom made it to the first knockout round.
In the other semi-final, Emre Can's Germany take on hosts France in Marseille on Thursday, looking to book a final showdown with Portugal at the Stade de France on Sunday.
The midfielder could be set for a first appearance at Euro 2016 with injuries and suspensions taking away some of Joachim Low's other options for defence and midfield.
Capped five times, Can has yet to make an appearance outside of a right-back role for the reigning world champions.