Interim Birmingham boss Gary Rowett rued a missed opportunity to move out the Championship relegation zone after the Blues were beaten 1-0 at home by Cardiff.
Rowett’s side would have moved out the bottom three with a point but Josh Bowler’s 65th-minute goal earned Cardiff victory at St Andrew’s.
The result leaves Blues 23rd in the table with just four games of the season remaining.
“When you have an opportunity, you have to do everything you can to take that opportunity and we just didn’t do that,” Rowett said.
“We petered out with a little bit of a whimper and it’s incredibly frustrating and frustrating for the fans who came out in good numbers.
“I thought we started OK and I thought we had some good control and I felt we got into some good areas without finding the quality to open them up.
“We’ve given goals away far too easily, we’ve conceded soft goals, tonight we had a chance to react to their goal and we didn’t react.
“We lacked character in that second half and how the game ended.
“We know we’ve got another tough game on Saturday and we need to show a little bit more urgency, fight and character.”
Cardiff, who remain in 11th position, lost midfielder Aaron Ramsey to injury.
The Wales midfielder started his first match for the Bluebirds since September but was substituted at half-time because of a hamstring problem.
Manager Erol Bulut said: “He had an injury with the hamstring so we hope it is not something big and we will see after a scan.”
Bulut was happy with his team’s display against a difficult opponent.
“It was a good game from our side, of course it was not an easy game because Birmingham are fighting for points,” Bulut said.
“It was a strong game from us against the ball and we could have made one or two more goals if we would have finalised our passes or the last shot but in general, I am satisfied with the performance of the team.
“We now have four more games and I hope it can be the same like today.”
Bulut believes it has been a satisfying season for the Bluebirds, but inconsistencies have been their downfall.
“You see where Cardiff City was last season and where they are now and how we have progressed, I am satisfied with the season and the performance of many players, but it could be better,” Bulut said.
“We have not had the consistency and so maybe we could be closer to the play-offs.”