Report: Aguero gives Man City edge over Sunderland
Sergio Aguero served up a reminder that there is life before Pep Guardiola as Manchester City maintained their Premier League title challenge with a hard-fought victory at Sunderland.
The Argentina international's 17th goal of the season was enough to claim a 1-0 win at the Stadium of Light, where the Black Cats suggested they could yet dig themselves out of relegation trouble.
City were far from at their best and it took fine saves by keeper Joe Hart to deny Jermain Defoe, who found himself embroiled in a running battle with defenders Martin Demichelis and Nicolas Otamendi, Billy Jones and substitute Wahbi Khazri in front of a crowd of 38,852.
But Aguero's 16th-minute strike proved sufficient to keep current boss Manuel Pellegrini, taking charge of his 100th Premier League game, on track for an unprecedented quadruple.
Pellegrini redeployed his big guns as Hart, Demichelis, Yaya Toure, David Silva and Aguero returned, but his men did not have it all their own way by any means before the break.
Sunderland, with debutant Lamine Kone in central defence and Jan Kirchhoff, who had endured a nightmare debut at Tottenham, sitting in front of the back four, gave as good as they got, summoning up a commendable resilience after falling behind and going in at half-time unfortunate not to be on terms.
The visitors took the lead with 16 minutes gone when Jesus Navas' driven cross fell nicely for Aguero, who controlled and stabbed home nonchalantly with the outside of his right foot, his eighth goal in as many games.
He might have added to his tally 11 minutes later when his shot from the edge of the box was partially blocked by Yann M'Vila and looped onto the roof of the net.
However, the Black Cats responded and should have been level with 34 minutes gone when Kone met Jeremain Lens' free-kick unopposed, but headed wide of the target.
Lens himself was denied a clear shot at goal when the impressive Kirchhoff tried to collect Fabio Borini's 41st-minute pull-back, but only succeeded in diverting out of his team-mate's path.
Toure's nimble footwork got him in on goal two minutes later, but he blazed high over, and the home side came desperately close to levelling as time ran down when Defoe turned Otamendi and saw Hart claw his left-foot strike away before Jones thumped the rebound against the outside of the post.
Both managers made changes at the break with Sam Allardyce sending on £9million signing Khazri for Lens and Pellegrini replacing Iheanacho with Fernando, in the process releasing Toure for more attacking duties.
Sunderland took the game to city in the early stages with Khazri prominent from the right, but as Toure and Silva started to make their presence felt, the visitors stemmed the tide.
Aguero shot straight at keeper Vito Mannone after Fernandinho had recycled a 61st-minute Navas corner, but Hart had to dive to his right to claw away Jones' 78th-minute strike and then react smartly to repel Khazri's corner and preserve his side's lead.