Celta Vigo 0 Manchester United 1
Marcus Rashford's splendid free-kick secured Manchester United a hard-fought win at Celta Vigo to edge Jose Mourinho's men closer to the Europa League final.
England's last European representatives have travelled far and wide in their bid to win the only major continental trophy to have eluded them in their success-laden history.
Europa League glory also offers a route back to the Champions League - an increasingly important option given their Premier League struggles - and Mourinho's men are in the driving seat of this semi-final after Rashford's fine free-kick secured a 1-0 first-leg win at Celta.
The away goal could prove crucial ahead of next week's return fixture at Old Trafford, where the Spanish side face an uphill battle to progress from their first major European semi-final.
Daniel Wass had given United an early scare but the visitors edged the first half, with Celta goalkeeper Sergio Alvarez staying strong to thwart Rashford, Henrikh Mkhitaryan and Jesse Lingard.
Sergio Romero did well to deny Pione Sisto as Celta threatened to punish United's all too familiar lack of killer instinct, only for Rashford to step up to the plate yet again.
Having sent United through to semi-final with his extra-time strike against Anderlecht, the 19-year-old settled the first leg with a second-half free-kick that sent the away support - and Mourinho - wild.
The importance of this occasion to Vigo was palpable as monuments were draped in sky blue, ribbons tied to taxis and streets lined with posters reading 'This is Afouteza' - the Galician word for bravery.
Local pride was clear and the din remarkable as the sides stepped out at Balaidos, where Wass wasted the chance to make himself a hero by nodding Nemanja Radoja's fine early cross wide.
It was a let off for a United side that restricted Celta to long-range efforts for the remainder of a first half in which goalkeeper Alvarez was key.
United's first shot did not arrive until the 20th minute but when it did the hosts' goalkeeper had to be at his best, producing a save just as superb as Rashford's 20-yard effort to keep it scoreless.
Lingard just failed to get a telling touch on a Mkhitaryan cross as the visitors looked to take the advantage in an entertaining first half.
The latter has been so key in this run and could - and perhaps should - have struck on a fifth successive European trip, only for a poor finish from Paul Pogba's side-splitting pass to be denied smartly by Alvarez.
Celta fans chanted their goalkeeper's name and were thankful to him again as half-time approached after denying Lingard.
Pogba struck over early and Iago Aspas directed wide early in the second half, with the superb reactions of United goalkeeper Romero preventing Sisto's deflected effort finding the net.
Tensions were growing as the wait for a breakthrough continued, with the relief clear from Mourinho's celebrations in the 67th minute.
Rashford and Daley Blind stood over a free-kick just over 20 yards from goal. The latter ran over it and Rashford punished wrong-footed Alvarez by fizzing home a right-footed strike home.
Mourinho headed towards the away fans punching the air at a goal that former Liverpool forward Aspas tried to cancel out, before Lingard lashed wide at the other end.
Tempers frayed as Rashford took his time leaving the field after being substituted and Marouane Fellaini avoided a second booking, with issues continuing on the touchline as the match entered the final minutes.
Celta pushed for a late leveller but, try as they might, it did not arrive.