Jose Mourinho said his Manchester United side were "ridiculous" to allow Tottenham to take an 11-second lead at Wembley before going on to secure a comfortable victory.
Christian Eriksen scored the third-fastest goal in the history of the Premier League to shock the visitors, who then gifted Spurs their second as Phil Jones turned Kieran Trippier's cross into his own goal.
Tottenham had to settle for a 2-0 win even though they dominated for much of the contest, Hugo Lloris only once forced into serious action to keep out Romelu Lukaku.
Mourinho cut a glum figure as he watched on from the touchline, with Manchester City’s win against West Brom leaving United 15 points adrift of their rivals.
The Portuguese felt his players had forgotten everything from their planning ahead of the game and counted a number of mistakes before the Red Devils had even had a touch of the ball – even if he felt the goal could have been disallowed.
“I don’t think it is very normal to concede a goal like we did after 15 seconds,” he said.
“It is especially ridiculous because the players, they watch it before, we analyse opponents and work on opponents’ dynamics and routines.
"The players they knew the long ball, they knew that Harry Kane – before the kick-off, is already inside the opponent's half. We knew everything.
“Then we don’t press the ball – one mistake. We don’t pick the ball in the air - second mistake.
“We don’t win the second ball on the ground – third mistake. We don’t cover the inside when Eriksen comes – four mistakes.
“Four mistakes after 15 seconds and you are losing 1-0 against a good team. Then I think [we had] a good reaction.
“He [Kane] was [in our half] – if the linesman or if the referee see it, of course, it wouldn’t be a goal, but it wouldn’t be fair for me to blame the referee.”
Mourinho confirmed Marouane Fellaini was forced off with an injury just seven minutes after replacing the ineffectual Paul Pogba and conceded, with Liverpool just three points behind in third, the race to finish in the top four is going to the wire.
“I always think when the leader has a certain distance, I have been there a few times, you are calm, you are relaxed and you don’t feel the pressure,” he added.
“You know that your opponent, sooner or later, is going to drop at least a couple of points and you are completely in control.
“We play match after match, yes the Premier League finishes for us at Old Trafford in May against Watford but you knew the distance to the leader was already considerable even before this match.
“Now we have us, Chelsea, Spurs, Liverpool, Arsenal – we will be there fighting for the positions.”
Tottenham's win puts them just two points off the top four – and six clear of neighbours Arsenal – with Mauricio Pochettino delighted with the performance of his team, Eriksen in particular.
“I think it was a great performance from Christian,” he said.
“Christian is such an important player for us not because today he was great and he scored.
“But he’s a player that links everyone and of course when he’s not in the team we always miss him. He’s a player that you miss on the pitch.
“I think the performance was fantastic and we played so well. The team deserved a lot of credit, a lot of credit.”
New signing Lucas Moura was paraded around Wembley at half-time as Pochettino's attacking options are bolstered following his deadline day arrival from Paris St Germain.
