Ajax resisted Ligue 1 side Lyon's 3-1 home win to bag an aggregate score at 5-4 on Thursday in France, while United built on their one-goal advantage in the first leg for a 2-1 aggregate against Celta Vigo in Manchester, reports Xinhua news agency.
United's Belgian midfielder Marouane Fellaini opened the scoring for the hosts in the 17th minute when he headed home a perfectly placed cross from Marcus Rashford at the Old Trafford stadium, reports Efe.
United focused on preserving their lead from that point forward, with Celta Vigo having a slight edge in time of possession at half-time.
After the intermission, Celta produced most of the best scoring opportunities, nearly getting a goal in the 76th minute when a header by Swedish striker John Guidetti went just wide of the post.
The Spanish club finally got on the board five minutes before stoppage time when Argentine defender Facundo Roncaglia headed a Theo Bongonda cross into the far corner of the goal.
The visitors still needed another goal, however, leading to a frenetic final few minutes that saw United central defender Eric Bailly getting sent off for pushing his hand into the side of Guidetti's head; both teams were down to 10 men, however, because Roncaglia was ejected in the same altercation.
In stoppage time, the hosts had a chance to seal the victory but an apparent goal by Ander Herrera was disallowed for a foul. Three minutes later, Guidetti failed to score on one final chance inside the box.
"The boys didn't play a phenomenal match but they fought, they gave everything they had to give and I'm really pleased for them because 14 matches and we are in the final so it's good," United head coach Jose Mourinho said, as reported by the club's website.
Lyon, having lost the first leg 1-4 last week, had no other option than attacking from the first minute, only to see their fragile defence broken down by their Dutch opponents in the 27th minute, when Kasper Dolberg beat Lyon goalkeeper Anthony Lopes with a tricky shot.
Resilient Lyon made a strong comeback late in the first half with their top scorer Alexandre Lacazette's two goals in less than two minutes.
The hosts continued their attacking play in the second half. After Ajax player Donny van de Beek hit the crossbar, two substitutes managed to cut the deficit in aggregate to one goal for Lyon with nine minutes remaining, as Rachid Ghezzal headed Maciej Rybus' left-wing cross into the net.
Ajax defender Nick Viergever was sent off after receiving his second yellow card in the 84th minute. Four minutes later, Lyon wasted their best chance to level the score, as Maxwel Cornet saw his shot off the post.
Following the win, four-time European champions Ajax will meet three-time continental champions United in the May 24 final in Stockholm. The winner will secure a berth in the 2017-2018 Champions League group stage.
"I'm glad it's Manchester United. That's a great reward," Ajax chief coach Peter Bosz said after the win.
"We're going to see if we really can write history, because when you are in the final, the only thing you want when you get there is to win!"
Reacting on their final opponents, Mourinho said: "First of all two monsters -- the history of Manchester United and the history of Ajax is amazing.
"But for us (if we win) it's a trophy and the Champions League for next season. Finals are always fun, and the Europa League is a big, beautiful competition."
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
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