Jan Vertonghen gave the home side the lead in the second minute and they had the majority of possession until Seb Larsson scored a free-kick in the 31st minute to equalise for the Black Cats.
It looked like Costel Pantilimon had earned a point for Sunderland with over a dozen saves, until Eriksen collected Andros Townsend???s cross at the edge of the box to give the Londoners all three points, two minutes from time.
Jermain Defoe failed to score on his club debut for the first time in his career, as he faced his old club.
It appeared that Vertonghen had scored his second three minutes into injury-time but his effort was ruled out for offside.
Vertonghen opened the scoring for Tottenham in the second minute with their first real attack, after Kyle Walker???s cross in from the right wing. Eriksen knocked it down and when Wes Brown attempted to clear it, the ball fell to the Belgian defender whose shot came off John O???Shea and flew past Pantilimon.
Defoe was soon involved as he appealed for a penalty after he hit the deck in the box under the challenge of Vertonghen, but it wasn???t deemed a spot kick and the following corner was cleared by Kyle Walker.
Tottenham conceded a free-kick 40 yards from goal in the 10th minute after Rose barged into Billy Jones but Sunderland were unable to make it count and Walker cleared the pressure.
The home side appealed for a corner a minute later after O???Shea knocked the ball out of play, while under pressure from Nacer Chadli but the linesman signalled for a goal kick.
Sunderland managed their first attack in the 16th minute when Defoe linked up well with Steven Fletcher, but the ball had too much pace and the debutant couldn???t get it under control to play his team mate in.
A powerful left foot shot from Eriksen in the 26th minute was pushed over by Pantilimon just as it looked to be heading in under the bar. Fletcher had a good opportunity to level the game two minutes later as Jones sent a ball into the box, but he miss-kicked the ball and it went wide.
Vertonghen was penalised in the 29th minute after bringing down Defoe about 25 yards from goal, after the striker ran past Eric Dier. The defender continued to appeal for offside, even though the officials never stopped play.
Larsson stepped up and sent the free-kick over the wall and inside the goal, with Hugo Lloris unable to reach it as it snuck inside his right-hand post.
Harry Kane had a chance to give Tottenham the lead on the stroke of half-time but his shot bounced off the post and Pantilimon saved the rebound shot from Danny Rose.
Soldado should have scored shortly after the break but was unable to connect with Eriksen???s cross after the Danish international played a one-two with Walker to find space just outside the box.
Pantilimon saved from Eriksen, Kane and Chadli in quick succession to keep the visitors in the game as the hour mark approached. While top scorer Kane and Eriksen also sent efforts wide.
The game appeared to be heading for a draw until the introduction of Townsend in the 75th minute whose fresh legs aided the home side???s attacking line. Defoe was replaced by Danny Graham at the same time, with Black Cats manager Gus Poyet having admitted prior to the game that the striker wasn’t completely match fit.
With just 10 minutes to go Adam Johnson took a shot from 25 yards out that Lloris could only parry to Graham, who was unable to latch onto the rebound.
It was Townsend???s cross that set up the winner. The substitute raced down the right hand side and his cross to the edge of the box was perfect for Eriksen, whose shot bounced in off the post past a stranded Pantilimon.
Graham had a chance to salvage a point for the Black cats in the third minute of injury-time but Lloris got down quickly to push the ball wide.
There was more as Vertonghen???s disallowed goal came seconds later, to end a frantic final 15 minutes that takes Spurs above Arsenal in the Premier League table as the hosts moved up one place to fifth.
Sunderland remain in 16th spot, but they are only one point above the drop zone with the equal-third worst goal difference in the league of -14.
Tottenham Hotspur: Lloris (7), Walker (7), Dier (6), Vertonghen (7), Rose (7), Chadli (7), Stambouli (6), Dembele (7), Eriksen (8), Kane (7), Soldado (6).
Used subs: Paulinho (5), Adebayor (6), Townsend (5).
Sunderland: Pantilimon (8), Jones(7), Vergini (6), O’Shea (7), Brown (7), Van Aanholt (6), Johnson (6), Rodwell (6), Larsson (7), Fletcher (6), Defoe (7).
Used subs: Wickham (5), Graham (6), Buckley (5).
Man of the Match:??Costel Pantilimon (Sunderland).