Gabriel Jesus’ strike on the turn early in the second half was enough to separate the two sides, with the home side unable to register a single shot on target at Stamford Bridge.
As well as earning a vital three points against a potential title rival, the victory also saw Guardiola rack up an astonishing 221st win as City boss, surpassing the previous record held by Les McDowall.
Speaking on Matchday Live, Onuoha couldn’t fault City’s performance against the European champions, giving huge credit to the Catalan for the way he set up the team to combat Thomas Tuchel’s men.
“I thought from the goalkeeper to the frontline, everyone was magnificent,” the former City defender reflected.
“Everything just seemed to fit, tactically I think Pep got it spot on.
“I think he controlled the game at Stamford Bridge which not many teams will do this year and he did that through the players that he put in there and the system he put them in.
“For Chelsea, they could never get into the flow of the game, and even when they took off Kante to try and go more attacking, I think they got worse because that’s when they got more open and City created more chances.
“For Pep and the team, they’re very well drilled and understood what was required to win that game.
“They went in as an underdog (and) I hope that’s the last time (that happens) between now and the end of the season. They deserve more credit because they’re a fantastic football team.”
Victory at Stamford Bridge also kicked-off what could prove to be a huge week in City’s season in the best possible fashion.
On Tuesday, Pep Guardiola’s men travel to the French capital to lock horns with Paris Saint-Germain, before we take on Premier League leaders Liverpool at Anfield the following Sunday.
Nevertheless, Onuoha is confident that City will go into each clash with the correct mindset to get a result, regardless of the occasion or opposition.
He said: “One thing Pep does really well is that he takes it one game at a time.
“For us from the outside, we’re talking about this week of games and who we’re up against, but the fact is they will prepare for each one individually the right way.
“It’s a different calibre of opposition come Tuesday and then Sunday, but they get it, the players feel good and they’re getting closer towards their best.
“At the start of the season a few of them only had a few weeks of pre-season, but people are getting games now, Phil Foden’s closer to being fully fit, (Kevin) De Bruyne’s feeling his way back in as well, you’re bringing in (Raheem) Sterling and (Riyad) Mahrez off the bench as well.
“(Pep Guardiola’s) got options and the game is against PSG but ultimately it’s a Champions League game whether they play PSG, Club Brugge or RB Leipzig they approach it in the same manner.
“That’s why for me they’re the best, they take every game as seriously as the next regardless of the opposition.”