It should have been an evening when the home side played with a passion, befitting a group of players who have spent too many days looking at the montage of posters fastened to their stadium which commemorate the breath-taking 2012 title win - and who are now ready to write a new piece of history.
By the time City were shaken out of their inertia to do so, Sunderland had set-up a finale like that day two years ago, though the penalty area which Sergio Aguero stamped his mark on has now added a less fortunate name to its legend. Vito Mannone, the goalkeeper whose penalty shoot-out heroics at Old Trafford in February took Sunderland to the Carling Cup final, desperately struggled to wrap a hand around Samir Nasri's 89th minute shot, in a way which sent him flapping through the mud, swatting a hand at it, again and again, before the ball slithered over the line.
An inch more purchase from the goalkeeper's right glove might prove the difference between Sunderland's presence or absence from the Premier League, because Connor Wickham's two goals in ten minutes had certainly left Gus Poyet touching victory. Still six points adrift of safety with Chelsea and Manchester United among five to play, Sunderland look doomed despite their heroics - as Gus Poyet virtually admitted in his estimably charming way.
Pellegrini's despair would have been by far the deeper, though - masked as it was by that implacable demeanour of his. Since Chelsea outthought and outfought City here in mid-February, his side have lost that imperious swagger and that way of making three, four and five-goal hauls a regulation. The injury bulletin their manager revealed again conveyed the impression of a worn-out side. David Silva had missed the game - and City missed him - because of his long-standing ankle problem. Sergio Aguero's long absence with hamstring trouble left him incapable of more than 55 minutes' work. Vincent Kompany looked as unfit for combat as he had with his leg strapped up at Anfield four days ago. Yaya Toure's absence with a groin injury was felt most deeply of all.
The Chilean suggested that it was Sunday's defeat at Anfield which had damaged his players psychologically. “I think we couldn't take out of the mind the game against Liverpool so we couldn't play well,” he said. But the inspirational qualities, missing in Roberto Mancini and sought out in Pellegrini by City's owners, were missing when needed.
Nasri's late equaliser is more valuable than those City fans who issued a chorus of boos at the end may realise. City's best hopes now reside in Chelsea knocking Liverpool out of the title race. If they win at Anfield a week on Sunday and City win their games in hand, they could still edge out Brendan Rodgers' side on goal difference. Yet there can be no misunderstanding about the scale of the calamity which this result represented.
The physical pain they experienced from the start revealed that it would not be easy. Wes Brown's leap into Sergio Aguero - two feet off the ground in the seconds before his right foot slammed into Aguero's own - left the Argentine writhing on the turf and Brown lucky to have escaped scot free. Marco Alonso promptly performed an eye-watering air kick into Pablo Zabaleta's shin.
And though City managed to ease into a characteristically early lead - Alvaro Negredo robbing Lee Cattermole and finding Aguero, whose return pass Negredo allowed to run under his boot to set Fernandinho free to score, two minutes in - the first half revealed City's same capacity to make defending less than straightforward that we witnessed at Anfield.
For 45 minutes, Adam Johnson looked as dangerous as anyone on the pitch, delivering an in-swinging corner that John O'Shea leapt clear of the City defence to head wide. Fabio Borini was equally profligate - shooting when he should have squared to Jack Colback, after running to seize a clipped Johnson ball that Martin Demichelis could not drag down.
But there was always valour in Poyet's players. Colback, like Johnson, revealed promise - though hesitated a fraction too long before unravelling a shot when Johnson released him into the inside right channel. And then Wickham stepped up. A few months ago, he had looked like another big money 21-year-old drifting into oblivion, when Poyet pulled him back from a loan spell a Leeds United and said that Sunderland should view him as a new signing. He struggled in his comeback game at Liverpool three weeks ago but the quality of his finish revealed why Steve Bruce paid £8.1m for him - and why Poyet gambled on him in his desperate for the serviceable striker Sunderland had been missing.
It was the substitute, Emanuele Gianccherini, who was Wickham's supplier. The game had 18 minutes to run when he crossed for the striker to tuck in at the back post. Then his cross allowed him to get in ahead of Fernandinho to beat Joe Hart at the near post. Having saved City from embarrassment, Nasri might have scored a second of his own, but he blasted over at the death.
You could sense the reservoir of joy, flooding down the M62.
Man of the match Wickham.
Match rating 7/10.
Referee M Atkinson (West Yorskhire).