City host struggling Queens Park Rangers in the final round of fixtures today needing only to match rivals Manchester United's result at Sunderland to secure a first title since 1968.
"I'm very proud because I think my players worked very well this year," Mancini said. "Maybe on Sunday we don't win the title, but we have played the best football in England."
City led the league for most of the season, until a wobble in March allowed United to establish an eight-point advantage.
But United's uncharacteristic slip-ups – losing at Wigan Athletic and throwing away a two-goal lead with 10 minutes to play in a 4-4 draw against Everton – allowed City to seize the initiative with a 1-0 victory in the Manchester derby 12 days ago.
"When I say that I want to win for our supporters, it's because I understand [they] don't win a title for maybe 50 years and stay in a city where our cousin wins every year," Mancini said.
City have also scored more than United while conceding fewer goals, meaning they can win the title on goal difference.
"It's important to score enough goals to win the title, this is important," Mancini said. "I think we played for six or seven months the best football in the Premier League. It's impossible to play well for the whole year. For one month we had a problem, but this is normal."
United know their chances of winning the title rest on QPR, a team who have lost 13 of their 18 away games this season, earning a point at the Etihad Stadium.
"We cannot think about what City are doing," Patrice Evra, the United captain, said. "We just have to make sure we win.
"The Sunderland game isn't easy but if we score first then maybe the City fans in the stadium will start to get nervous. When you are nervous then you can rush things and you don't do things as well as you'd like."
Sir Alex Ferguson, the United manager, last week reminded QPR's head coach Mark Hughes that he was dismissed by City in 2009. But Hughes said: "I wouldn't take any satisfaction from [thwarting City's title quest]. It would only be delight for my team and my players because it would be a huge achievement to be able to do that."
QPR need a point to avoid relegation, although they could stay up even if they are beaten if Bolton Wanderers lose at Stoke City.
Gareth Barry, the City midfielder, said Mancini had done a good job in taking the weight of expectation off his players, by writing off his side's title hopes when they fell eight points behind United.
Barry told the BBC: "He's taken lot of the pressure off the players, that's worked really well for us. We've really raised our game since a couple of disappointing results."
QPR also feature City old boys Joey Barton, Nedum Onuoha and Shaun Wright-Phillips among their playing ranks.
"It's going to be a really hard game," Barry said. "I've got a lot of respect for Mark Hughes, he had faith in me to sign me three summers ago. I speak to Nedum, when he left he said his worst nightmare would be for QPR to come in struggling for survival and us with a chance to win the league, so I'll leave the texts for after the game."
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