Swede says referee's decision was wrong
Sven Goran Eriksson has blasted his side's dismal performance which has hindered their push for a European place.
Man City went down 3-1 against a dominate Birmingham City side and the Swede was disappointed with how his team failed to challenge Mauro Zarate's brace.
"If you concede goals like that you will never win a game in the Premier League and that is not the normal Manchester City so we are not happy at all," he said.
"I think when we have the ball we should play much better, we did it in parts but we were poor today."
Man City failed to trouble Birmingham's Maik Taylor with Benjani struggling as a lone striker in the second-half and Darius Vassell barely getting a touch of the ball.
After Zarate's clinical double, Sven's men looked to have forced a comeback when Franck Queudrue was given his marching orders after bringing down Benjani.
But after Elano dispatched the resulting penalty, the away side were on the receiving end when Gary McSheffrey won a penalty as he went down in the box from a Sun Jihai challenge.
"We were not helped by the referee with the decision he took when he conceded a penalty against us," Eriksson added.
McSheffrey stepped up to convert the spot-kick for 3-1, leaving Man City needing to get back to winning ways to keep their dreams of a European spot alive.