The visitors went ahead 16 minutes into the game with a classy bit of finishing from Aguero and at that stage the travelling fans might have expected their side to cruise to a similar scoreline to the 4-1 win recorded when the two sides met earlier this season.
But Manuel Pellegrini’s team failed to test Sunderland goalkeeper Vito Mannone enough and the home side could easily have sprung a shock had they done better with three clear-cut chances before half-time.
The second half was almost completely dominated by Sunderland, but they were unable to breach City’s defences as the visitors preserved the three-point gap that separates them from leaders Leicester City, their next opponents.
A day that began with newspaper headlines trumpeting Guardiola’s arrival from Bayern Munich at the end of the season ended with Pellegrini celebrating victory in his 100th Premier League game at the City helm.
With City having reached the League Cup final and made progress in the FA Cup in recent weeks, Pellegrini had called on his players before the game to step up their challenge for the league title.
He backed that call up by fielding his strongest side available and that meant returns for Joe Hart, Martin Demichelis, Yaya Toure, David Silva and Aguero, who started alongside FA Cup hat-trick star Kelechi Iheanacho.
Sunderland handed full debuts to January defensive reinforcements Jan Kirchhoff and Lamine Kone, both of whom impressed, as manager Sam Allardyce prepared for a night when his side would have expected to be under the cosh despite home advantage.
Sunderland made a solid start, but were undone by a piece of Aguero brilliance.
– World-class Hart save –
The Argentine started and finished a move that culminated in him taking a right-wing cross from Jesus Navas, wrong-footing right-back Billy Jones and deftly lifting the ball home across Mannone from 10 yards.
City threatened occasionally, but it was Sunderland who stepped up thereafter and both debutants might have got on the scoresheet.
First Kone headed wide from Jeremain Lens’s free-kick in the 34th minute with the goal at his mercy before, six minutes later, Kirchhoff slid in to direct a good chance wide at the near post from a left-wing cross.
Seconds before half-time, Sunderland looked certain to score only for Hart to deny Jermain Defoe from point-blank range with a world-class save. Jones’s follow-up from a couple of yards out smashed off the post.
Suitably encouraged, Sunderland stormed out of the blocks in the second half.
Allardyce brought on another debutant, attacking midfielder Wahbi Khazri, while Pellegrini swapped Iheanacho for holding midfielder Fernando.
City had to weather solid pressure, but for all their domination Sunderland were unable to properly test Hart again until the 77th minute when a Jones pile-driver was palmed wide by the England shot-stopper.
From the resulting corner, either Khazri or Sunderland skipper John O’Shea might have scored, but Hart’s goal survived.
There were a couple more scares, but City held firm to maintain their chances of handing Guardiola a league crown to protect when he sweeps in from Bavaria.