Sebastian Larsson's free-kick looked set to seal a point for the Black Cats, only for the former Ajax man to strike from long-range for Mauricio Pochettino's side
Spurs took the lead after just three minutes when a poor clearance allowed Jan Vertonghen to power home a deflected strike, before the Belgian then gave away a free-kick from which Sebastian Larsson curled home a wonderful 31st-minute equaliser.
Harry Kane rattled the post before the break as Tottenham applied some pressure, but it was Eriksen who won it for the hosts with two minutes to play.
It could even have been three late on, but Vertonghen had an effort ruled out for offside, despite appearing to be in his own half when he collected the ball.
All eyes in the build-up were on Jermain Defoe, who was thrust immediately into the fray against his former club.
His arrival is designed to boost Sunderland’s attacking options, with Gus Poyet's side starting the game with just 18 goals in 21 Premier League games - the second worst record in the division, behind only Aston Villa.
However, it was Sunderland's problems at the other end of the pitch that were exposed after just three minutes, when Eriksen's cross was cleared only as far as Vertonghen, whose shot inside the area took a wicked deflection off John O'Shea to wrong-foot goalkeeper Costel Pantilimon.
Tottenham continued to press, as Eriksen forced a smart save from the Romanian 15 minutes later with a firm drive, before Roberto Soldado - who retained his place after the FA Cup win over Burnley - saw an effort smothered after being played in by Vertonghen's long ball.
Pantilimon produced another great save to deny Eriksen's 25-yard strike after 27 minutes and those heroics should have been rewarded a minute later, but Steven Fletcher failed to connect with a ball flashed across goal from Billy Jones.
Sunderland grew in confidence and they drew level just after half-an-hour when Larsson curled home a wonderful 30-yard free-kick after Defoe had been brought down by Vertonghen.
Kane nearly marked his return to the Tottenham side with a goal on the stroke of half-time, only for his drilled effort on the edge of the area to cannon back off the post.
Kane set up Soldado two minutes after the restart, firing a low cross from the right that just eluded the Spaniard at the far post.
Soldado was soon replaced by Emmanuel Adebayor as Mauricio Pochettino's men searched for another breakthrough, but Sunderland remained firm to restrict their opponents.
Nacer Chadli did manage to test Pantilimon seven minutes later with a well-placed half-volley on the edge of the area, before Adebayor forced a simple save with a tame left-footed volley.
Defoe, meanwhile, was withdrawn with 15 minutes left to be replaced by Danny Graham.
With two minutes left Tottenham's industry finally paid dividends when a wonderful counter-attacking run from substitute Andros Townsend allowed him to pick out Eriksen on edge of the area, and his lashed effort clipped the post on its way in.
It was nearly made even better for Pochettino's men before the final whistle, as Pantilimon's decision to go up for a corner allowed Vertonghen to breakaway and finish into an empty net, only to be contentiously ruled out for offside when he appeared to have taken the ball from his own half.