By Martyn Herman
LONDON (Reuters) - When Roberto Mancini was named Manchester City manager three years ago even the most optimistic of the club's supporters would have struggled to believe that Manchester United could be knocked off their pedestal so quickly.
Decades of disappointment and false dawns meant the key to the City trophy cabinet had been redundant since a 1976 League Cup triumph, after which a succession of managers tried and failed to drag them out of United's shadow.
Even the "golden ticket" of an Abu Dhabi United Group takeover in 2008 failed to convince some of better times ahead and Welshman Mark Hughes, the first manager tasked with molding the world's top talent into a title-winning side, was shown the door after an unspectacular start to the season.
The charismatic Mancini endeared himself immediately to the fans by sporting a blue and white scarf on the touchline but even he admits he is surprised by what has followed.
"When I arrived here three years ago I didn't think that maybe we would win in two years the FA Cup and the Premier League," Mancini told reporters on Friday.
"I thought maybe we would need four or five years to win the Premier League because it's not easy to change things in England because for 20 or 30 years Manchester United won everything and we've changed this situation.
"That's not to say we didn't make some mistakes because that's normal. And we need to work harder to improve."
Bottom club Reading visit the Etihad Stadium on Saturday, almost three years to the day that Mancini took over, with City locked in a dogfight with United as they seek to retain the Premier League title they clawed away from their rivals in May.
While a second successive Champions League flop has been a major disappointment, City's defense of their English crown has so far been tenacious, even if they trail United by six points heading into a four-game holiday program.
Mancini offered up Champagne to reporters at the club's training ground on Friday, a stylish touch at the onset of the holiday season. But behind the smile there is clearly substance.
The Italian, who steered the club to the FA Cup in his first full season in charge and third-place in the Premier League, has coped admirably with a dressing room full of millionaires, instilling a team ethic despite high-profile bust-ups with the likes of Carlos Tevez and Mario Balotelli.
For a club always associated with wildly fluctuating fortunes, tears and moments of hope, Mancini's reign has been almost boringly efficient.
Until a 3-2 defeat by United, City had gone 37 home games in the Premier League undefeated. Yet they responded to that disappointment with a 3-1 victory away to Newcastle United and Reading should be put to the sword on Saturday.
Mancini boasts 70 wins from 114 Premier League matches and only once have City suffered back-to-back defeats with him at the helm and that was more than two years ago.
If United are to reclaim their title at the end of the season they know they will have to earn it the hard way as Mancini's City battle-hardened side will not be handing it over without a scrap.
(Reporting by Martyn Herman)