Manchester United’s run of eight games without defeat came to an end at Wembley Stadium in front of a record crowd for a Premier League game.
Although United maintain a three-point gap over third place, the result enabled Manchester City to extend their lead at the top of the table to 15 points after the Blues beat West Bromwich Albion 3-0.
Spurs were ahead after just 11 seconds. A long ball forward found Deli Alli and as the England international tried to turn in the United area, the ball ricocheted off Chris Smalling and fell fortuitously into the path of Eriksen. The Dane made no mistake from close range to score the second-fastest goal in Premier League history.
Anthony Martial then looked to create a chance and after taking on Davidson Sanchez out wide, he was able to cut inside from the right to unleash a shot, but his effort lacked accuracy and sailed off target.
10 pics from Tottenham Gallery
View some of the images that were captured at Wembley on Wednesday.
Tottenham's pressure in United's final third soon yielded a second goal. Eriksen produced a dangerous cross from the right flank and, in trying to steer it behind for a corner, Phil Jones could only direct the ball past a helpless De Gea.
Mourinho: The second goal killed usVideo
Approaching the break, the Reds found it challenging to mount an attack as Spurs, high on confidence, pressed high up the field and restricted most of United’s possession to the visitors' own half.
The Reds had a fair shout for a penalty nine minutes into the second period when Alexis’s header hit the arm of Son, but referee Andre Marriner was unmoved.
Eriksen had his eye on a brace just after the hour mark and saw a dangerous strike from outside the box drop just wide of De Gea’s right-hand post.
As Jose Mourinho’s side searched for a way back into the match, both Juan Matta and Ander Herrera were introduced to bolster the attack, but Tottenham were content with their lead and began to sit in, making them increasingly difficult to break down.
Overall it was a frustrating evening for the Reds, made even more so by the fact that if there had not been such decisive poor fortune in the early stages, it could have been a very different night under the Wembley arch.
Tottenham: Lloris (c); Trippier, Sanchez, Vertonghen, Davies; Dier, Dembele (Wanyama 92); Eriksen, Alli (Sissoko 87), Son (Lamela 81); Kane.
Subs not used: Vorm, Rose, Walker-Peters, Llorente.
Booked: Dembele, Ali.
United: De Gea; Valencia (c), Smalling, Jones, Young; Matic, Pogba (Mata 63); Alexis, Lingard (Fellaini 63 (Herrera 70)), Martial; Lukaku.
Subs not used: Romero, Rojo, Shaw, Rashford.
Booked: Jones, Young.
The Reds are back in action in just three days’ time (Saturday 3 February) when Huddersfield Town visit Old Trafford in the Premier League. Kick-off is at 15:00 GMT.