March 7 (Reuters) - Manchester United ( MANU ) manager Ruben Amorim was happy with his side's performance in their 1-1 Europa League draw at Real Sociedad on Thursday but said the match drifted away from them after the Spaniards equalised from the penalty spot in the second half.

Joshua Zirkzee opened the scoring for United just before the hour-mark in the round of 16 tie before hosts Sociedad were awarded a penalty following a handball by Bruno Fernandes 10 minutes later, Mikel Oyarzabal making no mistake from the spot.

"I think we played well until the penalty. But then the penalty, I think, changed a little bit the momentum of the game," Amorim told reporters.

"I felt the team were a little bit tired in the last 20 minutes ... until the penalty, we were in control, had the opportunities."

Sociedad pushed for a late winner but Andre Onana kept United level with a couple of big saves in the final minutes.

Amorim also rued United's failure to capitalise on the chances they create, an issue which has dogged them in the Premier League where they languish in 14th spot.

"We are creating chances. Sometimes you don't see it in the (expected goals metric) because we manage not to shoot, but the great opportunity is there and you can see it," he said.

"We have transitions, we have situations, and sometimes we are missing something. And that can change, especially in this kind of game, that you need goals that can make a difference for everybody."

United host Sociedad in the second leg next Thursday. (Reporting by Chiranjit Ojha in Bengaluru; Editing by Peter Rutherford )