MANCHESTER, England, Sept 22 (Reuters) - Manchester City's 4-1 thumping of champions United evoked memories of a similar humiliation they inflicted on their red rivals two seasons ago with Manuel Pellegrini's new style of play adding real optimism to their title hopes.
The 6-1 victory at Old Trafford in October 2011 paved the way for City to claim that season's Premier League title on goal difference and, while Sunday's win at the Etihad stadium comes even earlier in the fixtures list, the message is the same.
Pellegrini said the defeat would be a "very big" psychological blow to his cross-city rivals, while midfielder Samir Nasri went even further.
"It's really special to win because we send a big statement to our rivals that Manchester City is going to be a force," the Frenchman, who scored the fourth goal, said.
"Today is a little bit of revenge. Last season everyone was sad because Robin (van Persie) scored a late free kick (to give United a 3-2 win in this fixture)."
There will be a lot of City fans who would never have expected to see such another comprehensive demolition of their decorated city rivals within such a short space of time but captain Vincent Kompany urged them not to get too carried away.
"It's too early to say it's a defining game," he told Sky Sports. "You make a statement over the course of the season. But it would be silly to give away three precious points.
"When we won 6-1 at Old Trafford I said we need to stay humble. It's only three points, but it's a good game to win and it gives the fans something to celebrate over the next few days."
City were simply a class - if not more - above United as the dynamic Jesus Navas, Nasri and Sergio Aguero ran riot, their pace and ideas more than making up for their lack of physical stature.
Aguero netted twice, with Yaya Toure and Nasri scoring the others as the more attack-minded style that Pellegrini promised to instil in the team when he succeeded the sacked Roberto Mancini in the close season started to show its potential.
A 4-0 hammering of Newcastle United in their opening game of the season had City fans drooling but, ultimately, that was against an even poorer team than Sunday's and Pellegrini's side struggled to create anything similar until now.
A shock 3-2 defeat by Cardiff City and a laboured 2-0 win over another promoted side Hull City inspired little confidence in a side who splashed out close to 100 million pounds ($160 million) on squad additions in the last transfer window.
There were glimmers of evidence that a corner had been turned in Tuesday's second-half performance at Viktoria Plzen in the Champions League, where all the goals in the 3-0 win came after the interval.
Pellegrini said that despite such a devastating display against United, they were not yet at their peak.
"I will be very happy if we win all the games 4-1...but I think we must improve every day," he told a news conference.
"We are just starting another style, another way to play, and I hope we will improve every day."
There will be plenty of teams, not least United, who will hope that is not the case. ($1 = 0.6250 British pounds) (Editing by John Mehaffey)