A breakaway goal from Mikael Forssell and some staunch defending after that helped Birmingham consolidate their place in the Premiership's top four. The Blues' third clean sheet in a row and their eighth of a parsimonious season underlined just how difficult to beat they have become, even though Bolton had the weight of possession to have put them under more pressure than they did.
''They're a delight to manage,'' said Steve Bruce of his overachievers. "Their efforts, attitude and application are outstanding. We set out to assemble a team that would be difficult to play against. That's what we're all about.'' Bolton can vouch for that, although they began brightly enough, getting a number of telling crosses into the Birmingham box, the most dangerous of which, from Ricardo Gardner, needed just a touch to put it over the line but eluded everyone.
It all went sour for them, though, when a mass appeal for a penalty after Kevin Davies appeared to have been climbed on - one of many penalty appeals in the game - distracted them from matters in hand.
David Dunn broke out of defence and fed Christophe Dugarry, whose prod into the box did not seem to present many problems until Simon Charlton, celebrating his 32nd birthday, lost his footing and left Forssell, on loan from Chelsea, in the clear to score.
"When you're struggling a bit, those things go against you,'' said the Bolton manager, Sam Allardyce, who could also consider his side unfortunate not to be level at half-time when Maik Taylor produced what Allardyce called "an outstanding, wonderful save'' to deny Davies's goal-bound shot from Jay-Jay Okocha's cross.
Bolton continued to spend plenty of time in the Birmingham half after the break, but usually found the twin barrier of Kenny Cunningham and Matthew Upson too secure for them to breach. They could have had a penalty when their Greek winger, Stelios Giannakopoulos, was tripped by Olivier Tebily in the area. Like Dunn in the first half, Stelios was booked for diving and, like Dunn, he could consider himself hard done by.
The Wanderers thought for a moment that they had an equaliser when Stelios's overhead kick found the net after Davies had hooked the ball to him, but he was clearly offside.
Bolton had been expected to start with Mario Jardel for the first time in the Premiership, but in fact held him back until the 65th minute. As time ran out, he had the last chance to retrieve something for his side, but the ever-willing Cunningham got in quickly to block his close-range shot.
"We couldn't hit a barn door at the moment,'' said Allardyce, as he came to terms with the loss of an unbeaten home record stretching back to January.
Bolton Wanderers 0 Birmingham City 1
Half-time: 0-1 Attendance: 25,023Reuse content