Adam Johnson, making his first start since injuring his ankle in January, opened the scoring in the ninth minute and skipper Carlos Tevez doubled the Blues' advantage on the quarter-hour mark from the penalty spot.

Second-half strikes from David Silva, Patrick Vieira and Yaya Toure completed a 5-0 rout that moves City above Chelsea into third place in the Barclays Premier League table by a point.

They are also now six points clear of fifth-placed Tottenham in the race for Champions League football, although both Spurs and Chelsea have a game in hand.

Mancini has frequently drawn criticism for his side's apparent conservatism, but with Tevez fit again having missed the 2-0 defeat at Stamford Bridge a fortnight ago with a groin problem, Mancini opted to pair the Argentina forward with Mario Balotelli up front.

Additionally boosted by the return of Johnson, it was a positive-looking team selection which paid off even more handsomely than Mancini expected.

"It was important for us to win this game because we had the chance to go into third position," Mancini said.

"Before the game I thought it would be difficult because it is not easy to beat Sunderland.

"They are a strong team who work very well and their manager knows everything. But we started the game brightly and that was important.

"I am surprised but I am happy. It is important that we scored five goals.

"It is possible (that it will give us confidence for our remaining games), but it is important now that we continue and go to Liverpool looking to win next Monday."

It will have made for an interesting afternoon's entertainment for Manchester United manager Sir Alex Ferguson, who was watching from the stands and will pit his side against City in the FA Cup semi-final at Wembley later this month.

Asked if he thought Ferguson might be worried by what he had witnessed, Mancini said: "I don't think so.

"He knows the FA Cup semi-final is one game in which anything can happen, and I think he knows Manchester City very well - like we know Manchester United."

While the season still holds much promise for City, Sunderland have now gone seven league games without a victory and need rapid improvement if they are to avoid being dragged into the relegation dogfight.

The Black Cats have 38 points after 31 matches and manager Steve Bruce believes it is not enough to guarantee survival.

He said: "We haven't got enough points in the bag, not when you see it.

"We are six points (above the relegation zone) and there are seven games to go. We have been on a horrific run.

"We have played some of the top six and we have found it very difficult with a half-fit squad, but that is not to make excuses. We have to arrest that."

Bruce also revealed his fears that defender Titus Bramble's season could be over due to a knee injury.

The club announced on their official website, www.safc.com, ahead of today's game that Bramble would not play after suffering cartilage damage, although it is not yet clear whether it is a recurrence of the problem the 29-year-old had surgery for earlier in the campaign.

"Bramble had an operation a few months ago and he has never felt quite comfortable," Bruce said.

"He had a scan the other day and he could miss the rest of the season.

"We've been told (he needs) complete rest at the moment.''

Another knee injury victim Fraizer Campbell, who has not made a first-team appearance for the Black Cats since August, had been expected to feature in the squad today but was ruled out as well after suffering a late setback.

Bruce said: "Fraizer Campbell twisted his knee yesterday in training and he will have a scan.

"We are keeping our fingers crossed that it is not a recurrence of the knee injury that he had in August.''