Cisse came off the bench to score a debut winner for Sunderland
Djibril Cisse scored on his Sunderland debut to condemn Tottenham to their second straight Premier League defeat.
Spurs, who dropped Dimitar Berbatov, were lucky not to trail at half-time after Steed Malbranque hit the post.
Gareth Bale powered a header over for the hosts soon after the re-start but they fell behind when Kieran Richardson rifled home after 55 minutes.
Spurs twice went close before Jermaine Jenas levelled but sub Cisse's late header left Tottenham without a point.
The build-up to the game was dominated by tales of two strikers.
Keane promises more from Sunderland
On Thursday Sunderland signed former Liverpool striker Cisse, who has twice fought back to full fitness after breaking a leg, on a year-long loan from Marseille, while Berbatov continued to be linked with a move to Manchester United.
Spurs boss Juande Ramos responded by leaving out Berbatov, who he said was lacking "focus", and the continuing uncertainty surrounding the mercurial striker seemed to affect the rest of the team.
With the Bulgarian absent Spurs started with Bale on the left of a five-man midfield and David Bentley in the middle of the park, while Darren Bent roamed up front on his own.
But despite enjoying the lion's share of territory and possession from the opening whistle they struggled to create chances.
All they managed in the first half were an off-target shot from Bentley and a couple of well-delivered corners from the England midfielder.
Sunderland, who had signed Northern Ireland international David Healy along with Cisse on Thursday, failed to create much themselves in a low-key opening 45 minutes.
However, they came desperately close to breaking the deadlock when Malbranque rattled a low 25-yard drive against the post with keeper Heurelho Gomes beaten.
Poyet refuses to blame absent Berbatov
Spurs were bright immediately after the re-start and Bale could have done better when he found himself unmarked on the edge of the six-yard box but powered his header from a corner over the bar.
Sunderland were not going to lie down, however, and took the lead when Richardson pounced after the ball was only half-cleared by the Spurs defence.
The ex-Manchester United player rifled a 25-yard drive just inside the far post to put the Black Cats into the lead, earning himself a booking for taking his shirt off as he celebrated.
Spurs immediately brought on Tom Huddlestone and Giovanni dos Santos, who had been warming up before the goal, and went close to an equaliser through Jonathan Woodgate and the previously anonymous Bent.
Cisse pledges to repay Keane with goals
Jenas then headed just wide as he beat Sunderland keeper Craig Gordon to a bouncing ball before, with 17 minutes left, he side-footed home the rebound after Luka Modric twice saw shots blocked.
Having levelled the scores it seemed Spurs would surely push on but once again they went off the boil and Cisse, who had come off the bench to replace Richardson, made them pay after 83 minutes.
When Daryl Murphy swung the ball over from the left the French international rose unmarked to power a header past Gomes and secure Sunderland's first Premier League win of the season.
Tottenham first team coach Gus Poyet: "Defeat is difficult to take because we really tried very hard to go and create chances, and we had a few, to change the result. They did their job - Sunderland really worked very hard.
"With only one striker 90 minutes is difficult and it is not the kind of game we want to play.
"We are used to playing with two strikers. Now we've got only one in the squad and it is very difficult."
Sunderland boss Roy Keane: "Tottenham had a right go at us, as you'd expect in the second half, but we maybe just about edged it. The good sign is I think there's a lot more to come from this team.
"Cisse has got that physical presence and the pace and we had a feeling amongst the staff that if he got on he could do a bit of damage to Tottenham and he certainly did.
"The players showed great character because it's always disappointing when you concede but Daryl Murphy has put in a great ball and it's great to win the game, particularly because last year our away form was so poor."
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