Brighton manager Roberto de Zerbi said defeat was hard to accept in the Europa League on Thursday.
The Albion were beaten 3-2 by AEK Athens in their group stage opener this week.
While De Zerbi was gracious enough to congratulate his opposite number on the success, he admitted that his side had more than enough chances to turn around the contest.
Post-game, De Zerbi said: We conceded three goals. Goals at set-pieces and one incredible goal.
We made mistakes in the last part of the pitch for example, Joao Pedro's chance in the second half or the chance for Igor in the first half.
But we played a very good game and I am very proud of the performance.
I think we showed not the right experience or but we played with personality, with the right attitude, the knowledge and we dominated the game.
We are sad for the result because we couldn't make our fans happy, ourselves, our club But we have to analyze the performance.
We can learn. We have to learn.
We can improve but it is difficult to accept this defeat.
I congratulated the players ten minutes ago.
I can't be happy when we win in Old Trafford and sad today if the performances are both good."