VIGO, Spain (REUTERS) - Manchester United striker Marcus Rashford struck a stunning second half free-kick to secure a 1-0 win at Celta Vigo in their Europa League semi-final, first leg on Thursday (May 4).

The victory puts United on course for this month's final, with Ajax Amsterdam the most likely opponents after they beat visiting Olympique Lyonnais 4-1 in their first leg on Wednesday.

Until the goal, United's finishing had been poor, with Celta keeper Sergio Alvarez thwarting them several times. However he was powerless to stop Rashford's 67th minute free-kick.

The visitors had the best chances in the early exchanges, though the Galicians made the first clear-cut opening for the unmarked Daniel Wass who headed wide from close range.

Rashford then forced Alvarez into a flying save from distance as Jose Mourinho's side got into their stride.

Alvarez then thwarted Henrikh Mkhitaryan and Jesse Lingard in one-on-one situations in quick succession before the break as United midfielder Paul Pogba's influence began to grow.

Celta started the second period brightly, with ex-Liverpool striker Iago Aspas heading just wide before Pione Sisto forced United keeper Sergio Romero into action with a deflected effort.

Rashford then put United ahead from 25 metres with a curling effort after winning the free-kick himself before gingerly leaving the pitch 10 minutes from time clutching his knee.

To add to United's injury woes, substitute Ashley Young was forced off with a hamstring problem in added time.