A great effort from the former Manchester United man along with the Italian's first of the season helps the Blues on their way to the next round of the League Cup
The hosts made several changes to the side that drew 2-2 with Fulham at the weekend, with Kolo Toure making his first start since coming back from his long-term suspension, as Mario Balotelli also started his inaugural match of the season.
But it was Hargreaves making his City debut that was the main talking point, following his move from neighbours Manchester United.
Birmingham meanwhile also made a handful of changes to the side to that that lost against Southampton last weekend, with manager Chris Hughton making a total of seven changes. Colin Doyle came in for regular keeper Boaz Myhill, whilst striker Adam Rooney got a start and Keith Fahey got an unexpected nod.City inevitably started the stronger of the two teams and would have had a clear chance if Balotelli could have navigated round the Birmingham defence, instead of diving to the ground in a non-existent penalty claim. The Italian attacker did get the hosts’ first shot on target just a few minutes later, but the former Inter player couldn’t test Doyle with his tame shot.
Debut delight | Good things come to those who wait as Hargreaves scores on return
Debutant Hargreaves opened both the scoring and his City account with a superb striker from 20 yards out, after Balotelli with his back to goal laid the ball off for the former Manchester United man and the midfielder sweetly put his foot through it, sending the ball into the corner of Doyle’s net.
Birmingham struggled to press as the first-half progressed, but following a free-kick on the left, Blues centre-back Curtis Davies attempted wicked overhead-kick that almost made its way into the City goalmouth, with Stefan Savic stopping it on the line.
Balotelli made it 2-0 to the hosts during a racing run down the wing by Aleksandar Kolarov in which the Serb placed the ball in the Italian’s direction in the box and the lone striker passed the ball passed Doyle and both centre-backs in front of goal.
The former Inter attacker nearly doubled his lead with an audacious curling shot from outside the Birmingham box, with the ball narrowly missing the bar of Doyle’s goal half way through the second period of play.
City continued to tease their visitors with accurate and at times, fast passing around the perimeter of the pitch at the Etihad Stadium. Birmingham threw on a substitute duo in Nikola Zigic and Morgaro Gomis, but they failed to make any impact.
Tevez should have made it three to City after going through on goal, but his and Toure’s follow-up couldn’t get past Doyle’s tremendous double save and the hosts went through on just the two netted chances.