Match ends, Tottenham Hotspur 2, Manchester United 0.
Manager Mauricio Pochettino praised Tottenham's "aggressive" opening as Christian Eriksen's goal after just 11 seconds helped them to a deserved win over Manchester United at Wembley.
The Dane latched on to flicks from Harry Kane and Dele Alli to side-foot home the joint-third fastest goal scored in the Premier League.
"You can win a game if you're ready to fight," said Pochettino. "It was massive to be up early in the game."
United responded well - with Jesse Lingard almost levelling - only for Phil Jones to turn Kieran Trippier's cross into his own net to double Spurs' lead.
Manager Jose Mourinho described the first goal as "ridiculous", and added: "The second goal mentally kills the team.
"To win matches a team needs to score goals and also defend well - on this occasion we were very bad."
Spurs looked sharper in a stretched game, and after goalkeeper Hugo Lloris maintained their advantage by denying Romelu Lukaku, Kane and Eriksen both went close.
Defeat ended United's eight-game unbeaten run in the league and left them 15 points adrift of leaders Manchester City in second.
Alexis Sanchez proved peripheral on his first league start for the Red Devils, failing to register a shot and touching the ball just twice in the Tottenham area as the home side, who are fifth, moved within two points of the top four.
Record crowd watch Spurs 'break' United
Eriksen's goal ignited a game packed with attacking intent and littered with chances. His calm, placed finish was also controversial, as replays showed Kane - who flicked the ball on to Alli in the build-up - was two yards inside the United half when kick-off was taken.
Neither side paused for such controversy as each set about testing the opposing defence, with Lingard unable to fully gather the ball when well placed and unmarked, before Anthony Martial was only denied by a fine Ben Davies tackle.
Kane, seeking a 100th Premier League goal, twice fired tamely at David de Gea, and the relentless pace ultimately proved too much for Jones as he miscued a Trippier cross into the net.
This was a United defence that arrived in north London having kept six straight clean sheets.
But, in front of a Premier League record attendance of 81,978, they wilted at the key moments and were outrun by their hosts, who clocked 116km to the visitors' 108km.
United boss Jose Mourinho pointed to confidence being "totally broken" after the second goal and his team simply could not find composure in the final third.
In a frantic game, moments of poise came from Eriksen and team-mate Mousa Dembele - the pair offering the best pass completion rates of any starting midfielder with 93% and 95% respectively.
United had their chances, notably when Paul Pogba headed over before the break and Lukaku was denied by a Lloris save on 56 minutes.
Marouane Fellaini was then substituted just seven minutes after coming on, the Belgian walking straight down the tunnel with a knee problem on a night of frustration for those in red.
Their advantage over Spurs is now down to five points as the fight for the top-four places heats up.
'Perfect night' as Moura watches
Spurs signed winger Lucas Moura from Paris St-Germain two hours before kick-off - and he was presented to the fans at half-time, walking to the centre circle before pointing to the sky with his eyes closed.
Manager Mauricio Pochettino called it a "perfect night" as business off the pitch complemented a complete display on it.
It is hard to see where Moura fits in, with Eriksen sublime on the right flank and Son Heung-Min a constant threat on the left. The Brazilian will know he faces a fight for a starting role as Spurs stepped up their level considerably from consecutive draws with Southampton and Newport County.
Eriksen's curled opener set the tone, and central defenders Jan Vertonghen and Davinson Sanchez nullified Lukaku; the shot count read 22-6 in the hosts' favour.
They were perhaps unfortunate not to be three up at the break - with Alli brought down by Antonio Valencia in the box - and Son and Kane dragged efforts wide after the break, while Eriksen smacked a 25-yard shot narrowly past the post.
But this was a timely success, taking their points haul to six points from a possible 18 against the league's so-called 'big six' before matches against Liverpool and Arsenal.
Those games will go some way towards defining if Tottenham will again be among Europe's elite next season - and they will be tough to stop if they continue to play like this.
'Mourinho got it wrong' - analysis
BBC Radio 5 live pundit Jermaine Jenas
It's been an unbelievable evening for Spurs.
Before the game I thought it would be end to end, but from the start United got worse and worse and just shrunk into themselves.
Spurs were dominant all over the park, it's been that brilliant it's hard to pick out a single player.
United lacked a competitive nature and Mourinho got it wrong. Lingard could be sacrificed for a midfielder that would protect Smalling and Jones, giving Pogba chance to go forward. They were wide open and Tottenham just enjoyed themselves.
Man of the match - Christian Eriksen
'It starts with a ridiculous goal' - what the managers said
Tottenham manager Mauricio Pochettino: "Our aim is to be focused from the beginning. It was massive to be up early in the game. Three more points puts us in a very good position to fight for the top four. I'm sure Lucas Moura enjoyed that a lot."
Manchester United manager Jose Mourinho: "It's a performance that starts with a ridiculous goal. That goal after a few seconds has a big influence in the game because Tottenham can play the way they like to play. The second goal kills the team."
Kane shoots more than Man Utd - the key stats
- Eriksen's goal was his 50th in all competitions for Spurs since joining in 2013 - second only to Kane at the club in that time (128).
- Jones' own goal was the third Tottenham have benefited from in the Premier League this season - more than any other side.
- Tottenham have won three successive home league games against United for the first time since September 1966.
- Kane had eight shots (including blocked), two more than the entire United team. Only twice in his Premier League career has he had more shots in a game without scoring (10 vs Burnley in August and Brighton in December).
- Lukaku has netted just 15 goals in 63 Premier League appearances against the 'big six' (Arsenal, Chelsea, Liverpool, Manchester City, Manchester United and Tottenham) compared to 81 in 147 against non-big-six sides.
Manchester United host Huddersfield on Saturday in a 15:00 GMT kick-off, while Tottenham travel to Anfield to meet Liverpool a day later (16:30).
- 6D Sánchez
- 19DembéléBooked at 13minsSubstituted forWanyamaat 90+1'minutes
- 20AlliBooked at 85minsSubstituted forSissokoat 88'minutes
- 7Son Heung-MinSubstituted forLamelaat 80'minutes
- 1de Gea
- 25A Valencia
- 4JonesBooked at 38mins
- 18YoungBooked at 73mins
- 6PogbaSubstituted forMataat 63'minutes
- 14LingardSubstituted forFellainiat 63'minutesSubstituted forHerreraat 70'minutes
- Andre Marriner
- Shots on Target
Second Half ends, Tottenham Hotspur 2, Manchester United 0.
Attempt missed. Erik Lamela (Tottenham Hotspur) right footed shot from the right side of the box is too high. Assisted by Christian Eriksen.
Offside, Manchester United. Ashley Young tries a through ball, but Juan Mata is caught offside.
Ben Davies (Tottenham Hotspur) wins a free kick in the defensive half.
Foul by Romelu Lukaku (Manchester United).
Substitution, Tottenham Hotspur. Victor Wanyama replaces Mousa Dembélé.
Offside, Manchester United. Alexis Sánchez tries a through ball, but Juan Mata is caught offside.
Attempt missed. Harry Kane (Tottenham Hotspur) right footed shot from outside the box is too high from a direct free kick.
Substitution, Tottenham Hotspur. Moussa Sissoko replaces Dele Alli.
Harry Kane (Tottenham Hotspur) wins a free kick in the attacking half.
Foul by Antonio Valencia (Manchester United).
Dele Alli (Tottenham Hotspur) is shown the yellow card for a bad foul.
Foul by Dele Alli (Tottenham Hotspur).
Alexis Sánchez (Manchester United) wins a free kick in the defensive half.
Ben Davies (Tottenham Hotspur) wins a free kick in the attacking half.
Foul by Ander Herrera (Manchester United).
Substitution, Tottenham Hotspur. Erik Lamela replaces Son Heung-Min.
Corner, Tottenham Hotspur. Conceded by Phil Jones.
Attempt blocked. Eric Dier (Tottenham Hotspur) right footed shot from outside the box is blocked.