The late goal glut was both unexpected and welcome, especially for City who had not managed a shot on goal until Elano's spot-kick.
It had been Sunderland who had looked more like scoring throughout the game, although Roy Keane's side were hardly in inspirational form themselves.
The Black Cats came into the match on the back of three straight wins that had seen them climb out of immediate danger at the bottom of the Premier League table.
But, Kenwyne Jones aside, they were unable to find a way through a makeshift City back-line that was missing Micah Richards and Nedum Onuoha through injury.
Jones has played a big part in Sunderland's consolidation in the top flight this season and showed why here.
The big Trinidad and Tobago striker was a constant thorn in the City defence and kept Richard Dunne busy all game.
Initially, Jones' industry did not translate into chances and a shot by Kieran Richardson that fizzed over the bar was the only early effort on goal.
Keane warns Sunderland are not safe yet
But the former Southampton striker almost made his mark when he ran on to Richardson's pass, out-muscled Dunne and fired in a shot that Joe Hart did brilliantly to block with an outstretched arm.
City were not creating much themselves but some decent crosses from the left boot of Martin Petrov kept Black Cats keeper Craig Gordon awake.
Most of the play, however, was compressed in midfield and fierce tackles and misplaced passes were the order of the day.
Things were similarly hectic after the interval and the home side's lack of quality when it mattered was shown by Daryl Murphy, who curled his shot high into the stands when he had time to pick his spot.
City seemed content to sit back and soak up Sunderland's pressure so it was something of a surprise when they scored on a rare venture into the home side's half.
Eriksson admits penalty was 'harsh'
Nosworthy will feel he was harshly adjudged to have clipped Sturridge in the area but that did not stop Elano from despatching the resulting penalty.
Understandably Sunderland reacted with urgency and three minutes later they were level - Whitehead meeting Reid's cross with a conclusive finish.
But City were not done yet and Elano volleyed over from six yards before substitute Vassell somehow scored the winner.
The former England striker ran on to Elano's pass and, although he failed to connect properly with his shot, he still got enough behind it to beat Gordon.
Only a superb double stop from Gordon prevented Petrov, and then Benjani, from extending City's lead but he could not save his side from an unlikely defeat.
Sunderland boss Roy Keane: "It clearly was not a penalty but we have to accept that and move on.
"I would have taken a draw at 1-1. To concede a second then and lose the game after we got back into it was particularly disappointing."
Manchester City boss Sven-Goran Eriksson: "We were lucky.
"There was contact for the penalty but it was still a bit harsh, and Vassell did not mean his shot like that.
"But I am very happy because we won away from home and our spirit was much better - we were fighting and defending well as a team."
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