His goal won three points against Doncaster at the weekend and his well-struck one at Ashton Gate built on a Bristol tragedy of an own goal by their skipper Louis Carey .
Two up in 24 minutes, the Blues looked to have built themselves a comfortable lead, but had to pull out every defensive stop in the second half to stay in front.
Carey's blunder came from a free-kick after James McFadden had taken a tumble just inside the left touchline.
Although Adriano Basso in goal looked to have Sebastian Larsson's long curling ball covered, he was played out of the action as the ball flew off Carey's head.
It gave the Midlanders that extra confidence and, with Jerome running hard in the middle, they began to beat the home side to the ball with regularity.
Their slickness soon brought them their second goal with Jerome slipping a left-footed shot past Basso as he met a shrewd through ball from David Murphy.
For City, Dele Adebola was always working hard to win his share of the ball in the air but as a team they lacked penetration.
They pressed on to win six corners in the opening half but nothing came of them.
They went closest with a Lee Johnson free-kick, while Michael McIndoe was a foot wide with a long-range drive.
Marshalled well at the back by Liam Ridgewell and Martin Taylor, Birmingham showed why they have given away only two league goals so far.
The home side lost Basso with an ankle injury and, within seconds of replacing him, Chris Weale was throwing himself down to smother a shot from McFadden.
The winger wasted a chance to wrap up the win early in the second half much to the agitation of his manager Alex McLeish .
City launched an earnest fightback which saw sub Lee Trundle pull back a goal with a 40-yard lob with 11 minutes left, but they couldn't find the breakthrough they needed to earn a point.