Manchester United boss Louis van Gaal was amazed that his side were so easily beaten by Arsenal on Sunday as they crashed to a 3-0 defeat at the Emirates Stadium.
The Red Devils entered the encounter in the capital sitting second in the Premier League standings, having been overtaken at the summit by neighbours Manchester City the previous day.
But they looked a shadow of the team that had performed so well in recent weeks as the Gunners raced into a three-goal lead inside the opening 20 minutes.
Alexis Sanchez produced a neat flick at the near post to open the scoring for the hosts on six minutes, before Mesut Ozil doubled their advantage just 60 seconds later.
Sanchez secured the three points for Arsene Wenger's side on 19 minutes with a powerful finish from just inside the area after he had beat three defenders.
United were never in the contest, although Anthony Martial did force a save out of Petr Cech later in the first half following a neat turn and shot that clipped the goalkeeper's leg.
Van Gaal expressed his surprise at the lack of effort from his players and their willingness to allow the hosts so much space throughout the match.
Commenting on the three early goals conceded, the Dutchman told MUTV: "I didn't expect that. I was surprised. No performing our game-plan, no will to win.
"We were top of the league so I was surprised – maybe 'amazed' is a better word. When you give a team like Arsenal so much space to play football, you know you shall lose.
"We have prepared ourselves in that way, to play more compact but not to lose our aggression. It was amazing for me and very disappointing.
"I don't know why it turned out like that. Normally I say things how I see them in the game. The players are in an emotional moment because we have lost. We have lost in a way you cannot lose when you are top of the league. You cannot start like that.
"The worst thing is everyone is flying away [for internationals]. So I cannot build a new situation to build up confidence. It is not a good preparation for the Everton game, but we have done it after Swansea when we beat Liverpool."