Gus Poyet could not control his emotions on the touchline. They were so close, leading through Connor Wickham's thunderous strike, his second of the evening, to a famous, priceless victory. But as Vito Mannone spilt his collection of Samir Nasri's effort, and the ball trickled across the goal line, Sunderland let slip three vital points.
Poyet permitted his side to express themselves and play without fear. They refused to be daunted by the imperious nature of City at the Etihad. They refused to be daunted by their five game losing streak. When City led through Fernandinho after only two minutes, Sunderland refused to be daunted.
Their attitude was excellent, their desire and commitment to retain Sunderland's standing in the Premier League evident. Fabio Borini ran himself into the ground, chasing lost causes. Adam Johnson, facing his former club, embodied the will in this Sunderland team, scampering down the right in defence and attack. Nevertheless, a victory would have suited them much better.
City's complacency was horribly exposed, Pellegrini's men punished dearly in the title race. They are now six points adrift of the league summit with a game in hand, effectively making the match between Liverpool and Chelsea on 27 April a play-off for the league crown.
They missed the power of Yaya Toure, the creativity of David Silva and the striking prowess of Sergio Aguero, who was largely ineffective on his full return from injury. The title is moving away from skipper Vincent Kompany's grip.
The Etihad faithful, with specks of empty seats around the arena, sang in defiance prior to kick-off. "We're Manchester City, we fight till the end." Javi Garcia stood in for the absent Toure with Silva a surprise omission from the match-day squad. Poyet, unlike at Anfield and White Hart Lane, selected a traditional back-four, ditching his preferred use of three centre-halves against the more superior sides.
City, contrary to the apathetic manner they would finish the game in, began vibrantly, taking the lead after only 107 seconds. Aguero, confirming his return from a troublesome hamstring injury, sprung forward, threaded the ball into Fernandinho via Negredo's intelligent dummy. The Brazil midfielder took the ball into his stride and finished in assured fashion. Sunderland were staring a rout directly in the eye.
However, their response was positive, unchaining their defensive locks to venture forward. O'Shea spurned two great opportunities, heading narrowly wide from inviting deliveries. City looked fragile from set-pieces, missing the height of the injured Toure and substitute Dzeko. Borini shot wide, so did Johnson. Their profligacy contrasted with Wickham's later verve and accuracy.The match gradually opened up. City poured forward in numbers. Mannone forced away Aguero's swerving strike before Fernandinho volleyed over when he should have examined Mannone. From another counter-attack, Negredo was unable to pinpoint the surging Aguero.The Etihad became a hub of anxiety for a brief moment as Aguero lay on the turf in pain, reeling from Wes Brown's strong challenge. The Argentine soon hobbled back into the action, short of his pace and strength to worry Brown and O'Shea, but he worried Wickham. The former Ipswich Town centre-forward was clumsy in his defensive duties, obstructing Aguero from the ball as City appealed for a penalty in vain.
After 55 minutes, Aguero duly departed with Stevan Jovetic his replacement. The Montenegro striker was immediately involved, forcing Mannone into a stop before he fired over with an exuberant bicylcle kick. He then drove wide from the target.
Pellegrini and Poyet were both positive in their thinking, the City boss searching for the decisive second goal with Poyet looking to rattle the hosts with an equaliser. Emmanuele Giaccherini and Argentine forward Ignacio Scocco joined the action before Edin Dzeko replaced Negredo, most probably for the Bosnian's sharpness from the bench, scoring 17 goals as a substitute.
Yet, he was profligate here, wasting a great opportunity to guide home Kolarov's wonderful pull-back. Despite their slight domination, Sunderland continued to pose a threat, scoring eventually through Wickham. The 21 year-old had been sought after by Liverpool in 2011 to help them towards a Premier League title, but he did in the red and white of Sunderland. Giacherrini scampered down the left flank and the Italian's excellent cross was guided home by the strong striker. It was no less than the visitors deserved.
City were visibly rattled, squandering possession fluently. Giaccherini, so effective since his introduction, latched onto a loose ball and sprung forward. Wickham was lingering beyond Demichelis and Giaccherini found him superbly for the England U21 international to thump the ball beyond Hart. The title slipped away from City, and as three points trickled away from Sunderland, Chelsea and Liverpool are in pole position for the league crown.