Southampton produced a gritty display to earn a battling point.
Birmingham had the best chances in a drab game, with David Dunn blasting over and Darren Anderton being denied by a fine save from Antti Niemi.
Southampton's Dexter Blackstock saw a header hit the bar and Mikael Nilsson should have done better than shooting wide after rounding Maik Taylor.
The Saints move off the bottom of the table and will consider it a worthy point, considering their injuries.
Southampton went into the game without a host of first-team players.
Their injury problems were so bad that Brett Ormerod was named on the bench, despite playing the full 90 minutes for Leeds only 24 hours earlier.
Birmingham were the first to threaten either goal as Anderton, making his first start in the League for Blues, shot high and wide from the edge of the box.
Rory Delap created Southampton's first chance when his long throw found the head of 18-year-old striker Blackstock, who was making his home debut, but his looping effort hit the top of the crossbar.
Emile Heskey's partnership with Dwight Yorke looked lively early on.
Heskey showed good awareness to play a perfectly-weighted pass into the feet of Yorke and the former Villa striker shot just wide from a tight angle.
Southampton's best chance of the opening half came when Fabrice Fernandes released Nielsen, who beat the onrushing Taylor to the ball.
But with an empty net in front of him he put his effort from a tough angle wide, with an unmarked Neil McCann pleading for him to square it.
Birmingham looked the more likely to break the deadlock in a second half that narrowly shaded a desperate opening 45 minutes in terms of entertainment value.
Dunn cut inside from the left and fired in a shot that Niemi spilled but Yorke made a hash of trying to tap in the rebound - and his embarrassment was only saved by the offside flag.
Heskey then held the ball up and laid it off for Mario Melchiot but his powerfully-struck shot rose just too high to trouble Niemi.
Dunn again found an opening on the left and unselfishly released Anderton but he looked anything but assured as he drove the ball wide of the near post.
Ormerod was brought off the bench for Saints to offer more support for an often isolated Blackstock.
But it was Birmingham who continued to look more threatening and Heskey produced a good turn before rolling the ball into the path of Dunn in front of goal.
But the winger looked like a player who had not found the net for 14 months as he skied his shot over the bar.
Anderton looked to have broken the deadlock when Jelle Van Damme's poor clearance fell invitingly for Anderton but his volley was brilliantly kept out by the left hand of Niemi at full stretch.
Southampton: Niemi, Kenton, Lundekvam, Jakobsson, Van Damme, Nilsson (Ormerod 64), Anders Svensson, Delap, McCann, Blackstock, Fernandes (Prutton 89). Subs Not Used: Blayney, Best, Higginbotham.
Birmingham: Maik Taylor, Melchiot, Upson, Cunningham, Gray, Anderton, Dunn (Clapham 81), Savage, Johnson, Heskey, Yorke (Gronkjaer 64).
Subs Not Used: Tebily, Bennett, Martin Taylor.
Ref: M Dean (Wirral).