Sixteen weeks after the dramatic season finale that saw City crowned Premier League champions at the same ground, the hosts survived another scare against the side managed by their former boss, Mark Hughes.
Despite creating a multitude of chances, City needed a quick response from Dzeko after Bobby Zamora cancelled out Toure's effort but Tevez made the scoreline more convincing in injury time.
Apart from QPR's recovery after falling behind, the match had little in common with that in May.
The visitors were hardly a factor for long spells and only three of their starting line-up were in the team that memorable afternoon.
Their changes included a debut for new signing Esteban Granero while goalkeeper Robert Green, dropped from the England squad this week, started what could be his last match as first choice.
The 32-year-old only joined the club in the summer but now faces an uncertain future following this week's capture of Julio Cesar from Inter Milan.
Scott Sinclair was the only one of City's five deadline day signings to make their squad but did not get off the bench.
City, watched by Real Madrid boss Jose Mourinho ahead of their Champions League meeting, soon established control with Toure bossing the midfield.
QPR survived a scare in the first minute when Dzeko, starting for the first time this season, glanced a header wide from a corner.
The Bosnian went even closer as he was first to meet another corner but this time Fabio da Silva, on loan from Manchester United, did well to hack off the line.
Toure powered in on the rebound but this time former City playmaker Shaun Wright-Phillips blocked.
The City pressure continued as Rangers were starved of possession and an Aleksandar Kolarov cross almost fell for Jack Rodwell after a touch from Tevez.
QPR's first opportunity came from a City mistake as Rodwell overhit a backpass and the ball dropped over his own bar for a corner. The visitors were unable to capitalise.
It seemed inevitable City would take the lead and their opener came in the 16th minute as Tevez saw an effort blocked from yet another corner but Toure followed up to thump home.
Green got a hand to it but could do little on what was shaping up to be a difficult afternoon for him.
Former Real Madrid man Granero had QPR's first shot when he found space outside the area but Joe Hart was not troubled.
David Silva tricked his way into the QPR box and dug the ball out from under his feet to force Green to save and Samir Nasri was unable to follow up.
Silva spurned another opportunity when he was played through by a superb long ball from Kolarov. The Spaniard failed to get away a shot quick enough and Fabio produced another timely block.
Tevez fired over as City continued to power forward and Rodwell wasted an opening when he opted to pass instead of shoot.
QPR's opportunities were limited but Granero looked composed when allowed time on the ball but missed the target with another attempt.
City returned for the second half with much the same approach as the first and threatened a second straight from the restart as Tevez drilled an awkward shot at Green.
The tireless Pablo Zabaleta, probably knowing new signing Maicon might be after his place, went even closer as he took a fine pass from Silva and curled an effort onto the bar.
Yet as much as they were dominant, recent history threatened to repeat itself as QPR levelled against the run of play just before the hour.
Andrew Johnson stole possession outside the area and forced a good save from Hart with a deflected shot. Hart could not recover his footing quick enough to regather and Zamora stole in to head home.
Yet in contrast to last May, City began their reply earlier and without falling behind.
They swiftly moved back up the field and Tevez did well to keep the ball in play and cross for Dzeko to head home at close range.
It should have been the sign for City to wrap up the game but despite continuing to carve out chances - Dzeko twice shooting only to be flagged offside - it remained a slender lead.
There were definite signs of nerves when Granero whipped in a free-kick and Ryan Nelsen narrowly failed to touch in at the far post.
City wrapped up the job in injury time as Tevez, moving back into an onside position, diverted the ball home from Dzeko's shot.
After apparently being told off for lifting his shirt in recent weeks, he kept it down this time.