Manchester United captain Paul Pogba claims that Brighton "had more hunger than us" after the Seagulls deservedly beat United 3-2 at the Amex Stadium on Sunday.
First half goals from Glenn Murray, Shane Duffy and Pascal Gross condemned United to their first defeat of the season, and Pogba's late penalty made it look closer than it was.
The Frenchman professed that his attitude, and that of his team, had not been appropriate for the match.
"We lost, we did not deserve to win," Pogba told Sky Sports after the match. "The attitude we had was not like we wanted to beat them, they had more hunger than us.
"I put myself first, my attitude wasn't right enough, we keep trying and pushing, and it is going to be a big lesson for us."
United's defending was at times highly questionable, with Brighton's high press giving Victor Lindelof and Eric Bailly a torrid afternoon.
Romelu Lukaku responded for United to halve the deficit after Murray and Duffy's goals, but just as they were getting back into the game, the visitors conceded a penalty and Gross restored the two-goal cushion.
"I think we made the mistake we shouldn't make," added Pogba. "You go 1-0 down, it's OK, then 2-0, then 2-1 and you have hope we can score again, but we concede a goal. It's a hit for us. In the first half it was a hit. It was very disappointing, we tried to push.
"You cannot always approach the game the same way as the last one. You always try to play better than the last game, but we know, and I know we can always play very good, but the attitude has to be good and we missed that today."
Next up, Manchester United host Tottenham next Monday.