Liverpool 2 Birmingham City 2
David N'Gog eased the Anfield nerves in the 12th minute when he volleyed home Albert Riera's chipped cross.
Christian Benitez ghosted in behind the Liverpool defence to head Birmingham level in the 26th minute, before Cameron Jerome smashed home an unstoppable 30-yard drive in first-half stoppage time.
But having thrown on Gerrard for the injured Riera moments before the break, boss Benitez was rewarded when his skipper fired home from the penalty spot after N'Gog went over softly in the box.
Despite losing five of their past 11 Premier League games, Liverpool had won their last three at Anfield and took the lead in the 12th minute.
Blues keeper Joe Hart kept out first N'Gog then Dirk Kuyt from close range but, after Riera chipped the ball back across the six-yard box, the young Frenchman smashed the ball home on the volley.
Yet in the 26th minute Birmingham were level when Roger Johnson and Scott Dann both won headers inside the Liverpool box before Benitez nodded home.
Deprived of Fernando Torres through injury, the Anfield crowd was momentarily lifted when Gerrard was brought on in place of the hobbling Riera in the 45th minute.
But while Gerrard was easing on the captain's armband, Jerome held off Javier Mascherano and unleashed a thunderous strike that gave Pepe Reina no chance and left the Reds trailing at the break.
Gerrard, so often Liverpool's saviour, looked to have dragged Benitez's men level when he connected with Glen Johnson's cross only to see his effort strike the post.
But with 20 minutes to go the hosts were level when N'Gog went down cheaply in the box and Gerrard swept home the controversial penalty.