All the goals came in an entertaining second half at the City Ground on Saturday.
After having the better of the first half, Forest found themselves behind courtesy of goals from Hayden Mullins and Marlon King in the space of three minutes.
Substitute Simon Cox quickly pulled one back for the hosts with a superb effort after 73 minutes before another sub, Dan Harding, levelled things up with four minutes remaining.
With Cox only fit enough for the bench following a foot injury sustained while on international duty with the Republic of Ireland, fellow summer signing Billy Sharp made his full debut for Forest alongside Dexter Blackstock in attack.
Leroy Lita was handed his Birmingham debut. The striker arrived on loan from Swansea last week and replaced Wade Elliott in the Blues' starting line up.
The hosts started brightly with Blackstock heading over from a corner following some early pressure.
A mistake by Jack Butland almost presented Sharp with his first Forest goal after 13 minutes. Butland spilled Sam Hutchinson's cross but Sharp's shot on the turn was straight at the England goalkeeper.
Butland was more assured soon afterwards when he did well to deal with a superb delivery into the box from Lewis McGugan.
A swift break by Forest should have seen them take the lead midway through the first half but Sharp, McGugan and then Adlene Guedioura could not capitalise after an almighty scramble in the Birmingham box.
After being on the backfoot for much of the opening 30 minutes, Birmingham nearly went ahead against the run of play.
Lita set up striker partner King but Lee Camp was quickly off his line to make a block. It was a brilliant piece of goalkeeping by the Northern Ireland international.
Daniel Ayala then denied King again from the resulting corner.
The final chance of the first half saw Andy Reid's free-kick from the edge of the area scooped over the crossbar by Butland five minutes before the break.
Birmingham boss Lee Clark made a change four minutes into the second half with the largely anonymous Peter Lovenkrands making way for Elliott.
Elliott got straight into the action, almost catching out Camp with a long-range shot but the Forest keeper held on to the ball at the second attempt.
Forest continued to get themselves into good positions but first Reid and then Greg Halford saw dangerous balls into the box narrowly elude team mates.
Cox came on after an hour, replacing Blackstock. But it was Birmingham's substitute Elliott that had turned the game in the visitor's favour since his introduction.
And Elliott was involved when the Blues took the lead after 69 minutes. He set up King whose shot was blocked by Hutchinson before Mullins fired a first-time volley into the roof of the net from 15 yards out.
Clark brought on Nathan Redmond for Chris Burke immediately after the goal, and it proved to be another masterstroke by the former Huddersfield manager.
Redmond evaded Halford and Reid down the right and cut the ball back from the byline for King who finished brilliantly from the edge of the area.
However, Forest's sub Cox had his say shortly afterwards. The Republic of Ireland international brought down Hutchinson's long ball forward with a sublime touch but his second touch was even better, brilliantly lobbing Butland to half the host's deficit.
Forest boss Sean O'Driscoll changed his formation to play three at the back as his side chased an equaliser, and it arrived with four minutes remaining.
Halford carried the ball deep into the Birmingham half before putting a deep cross into the box where Harding finished, with the aid of a deflection off Pablo Ibanez, at the far post.
Despite having the momentum the hosts did not push for a winner and had to endure some late Birmingham pressure to hold on for a point.