When Sergio Aguero joined Manchester City in the summer of 2011 for £35 million, he brought with him not only his reputation as one of the world's finest strikers but also a determination to change the culture around the Manchester derby.

City had long lived beneath the shadow of their cross-city rivals Manchester United, and the former Atletico Madrid forward recognised quickly that a shift in mentality was essential if that was ever going to change.

A debut season to remember

Aguero wasted no time making his mark, finishing his first Premier League campaign with 30 goals as Roberto Mancini's side mounted a serious title challenge. It culminated in one of football's most celebrated moments — his injury-time winner against QPR that sealed the title on the final day.

"That was a very important title for Manchester City," Aguero recalled in an interview with FourFourTwo. "Of course, it became a very, very correct decision to join the club, when we finished my first season as champions."

Changing the derby dynamic

Beyond the QPR moment, Aguero takes particular satisfaction in what City achieved against Manchester United that season. Mancini's men beat their rivals twice in the Premier League — a stunning 6-1 victory at Old Trafford in October, followed by a decisive 1-0 win at the Etihad in late April that proved pivotal in the title race.

"I have the best memories of the games against Manchester United that season," Aguero said. "Really importantly, we won them both. At that time, City were used to the idea that United were always better than them, and City could never beat them."

For Aguero, breaking free of that defeatist mindset was as important as any individual performance. He made it a personal mission each time the derby came around.

"When I started to face United, my mindset was 'This has to change — we have to think that we can beat them, that we can win the Manchester derby'," he explained. "In those games against United, I was able to fully concentrate. In my mind I always thought 'I have to score a goal against United, because we need to win this game.'"

Aguero credited focus and self-belief as the driving forces behind his derby performances, adding: "I was really focused, and luckily the matches often went pretty well."

That 2011/12 Premier League triumph remains one of the most dramatic title wins in English football history, and Aguero's influence — both on the scoresheet and in the dressing-room mindset — was central to it all.