But it did not take long for Dzeko to head City back in front, adding to Yaya Toure's opener, before an injury-time deflected effort from Tevez sealed victory.

"We have one problem at the moment - when we have a chance to score we don't score and after this the game can change," said Mancini.

"We had this problem in our first game. We had a problem against Liverpool. When you have a chance to score you should score.

"I think the problem could be we didn't work with our players in pre-season. Some players started their pre-season very late.

"At half-time, I said it's important we can't concede a goal every game - this is one of our problems - and when we get a chance we should score."

But City's first team coach David Platt insisted it was just a matter of time before the club found the form that enabled them to be crowned champions of England for the first time in 44 years last season.

"We're not quite at the levels we were last season at this moment," said the former England midfielder.

"This time last season, we were blowing teams away and keeping clean sheets.

"It's not that we're not playing well, it is that we're not playing as well as we did at the start of last season. There is an expectancy from ourselves, an expectancy from supporters.

"But we can look at the video of the game, watch it in its entirety, a lot more positively when we have won the game.

"The be-all and end-all is we stand here unbeaten with seven points out of nine and we know we can improve.

"When you look at the players' names written down, you sleep easy every night because they are good players."

Platt believes key personnel are still searching for early season fitness, something which he hopes will steadily improve over the coming 10-day international break.

And he also had good news concerning the forward Mario Balotelli who is having eye 8surgery this week to help cure persistent conjunctivitis.

"I think he's okay, it's just a normal procedure," said Platt. "He'll have an operation in the next couple of days and it's minor.

"We're not quite there yet in terms of fitness. After the international break, Gareth Barry will have had another two weeks (training), Sergio Aguero will be there or thereabouts, David Silva will have had another two weeks after playing in the Euros, plus we have the new faces who have come in as well."

QPR manager Mark Hughes, Mancini's predecessor at City, was disappointed his side failed to test the champions further.

But with seven recent signings in his starting line-up, it may take time to see the best from his team.

"I can take a lot of positives from the game," said Hughes.

"We were in the backyard of the champions, we put a great shift in and caused them problems."

The former Manchester United and Wales striker added: "We were in charge of the game when we equalised and to concede so quickly was a body blow."