Manchester United couldn't cope with Sunderland's "aggression" at the Stadium of Light.
That was the view of under-pressure United boss Louis van Gaal after watching his side slip to a 2-1 defeat to the Black Cats which landed a hefty blow to their hopes of a top four finish.
Anthony Martial cancelled out Wahbi Khazri's third minute opener but Sunderland dominated after the break and the visitors couldn't cope, Lamine Kone's header sealing the win after it was deflected in via the back of David De Gea.
The huge win has raised hopes that Sunderland can stay up this season, but Van Gaal's position at Old Trafford is under increasing pressure, with Jose Mourinho rumoured to be taking charge in the summer.
And the Dutch manager admits his side struggled to cope with Sunderland.
Van Gaal admitted: "Yes,it was a very disappointing afternoon.
"These kind of matches you have to win and I said that in advance. We didn't do that."
When asked what went wrong, Van Gaal added: "It was two set plays, we knew in advance they could score from set plays.
"I told the team, they had to recognise it as well. But the main reason is always in a match you will be compared with your opponents in aggression.
"And I think that Sunderland played with more aggression because they played with direct balls. Second balls are very important to win and they won a lot of them.
"We started very badly, the first 20 to 25 minutes but the second half of the first half we could cope with that aggression and we had our positional game.
"We scored a fantastic goal, I think.
"I had the feeling that we could cope with that aggression, in the second half, but Sunderland were even more aggressive.
"We lost a lot of balls in the second half, unnecessarily.
"From the set plays, they are always a threat. It was not the first time that happened."
With 12 Premier League games to go, United's top-four chances look bleak as Van Gaal admitted that winning the Europa League could be their only route into the Champions League.
"I think after this match that is the best route (into the Champions League and that is not so easy because there are a lot of very good teams participating in this event (the Europa League).
"It will be very difficult now. We give five points away, Chelsea and now this game so it is too much at this time.
"I have to do my work, and I do my work to my utmost best and I must prepare my players for Midtjylland."