Match ends, Birmingham City 2, Blackburn Rovers 4.
Rudy Gestede scored a hat-trick at St Andrew's as Blackburn recorded a comfortable victory to heighten Birmingham's relegation worries.
The away side went 3-0 up within the first 24 minutes, as Gestede struck twice before Todd Kane slotted home.
And Rovers grabbed their fourth on the stroke of half-time as former Cardiff striker Gestede headed in his third.
Lee Clark's men rallied. Nikola Zigic nodded in and Demarai Gray scored the second but the damage was already done.
The result leaves Birmingham in 21st position, one place above third-bottom Blackpool on goal difference, while Blackburn are now just two points off a place in the play-offs.
Gestede took just 10 minutes to get off the mark as he rose highest to head home Josh King's lob to the far post.
Ten minutes later, the visitors doubled their advantage as the same players combined with the same results, Gestede heading in King's free-kick.
Gary Bowyer's men effectively ended the contest after just 22 minutes when Kane's shot was deflected past the helpless Darren Randolph.
And a minute before the interval, Gestede completed a hat-trick of headers for a 4-0 lead. He could have had a fourth but saw his effort kept out by goalkeeper Randolph.
Birmingham pulled goals back through Zigic and Gray, but the defeat leaves them in deep trouble at the wrong end of the table, with three games remaining.
Birmingham boss Lee Clark: "I am confident in the players. We have to have the mentality that we have shown in second halves during this wretched run.
"We have to show this form from the first whistle. It seems that there is a domino effect. We concede the first goal and it results in two or three goals and four in the first half on this occasion.
"If we were to win our two home games then we should be okay.
"We were really punished and it was not good to watch. We responded well in the second half, but we certainly need to perform and our future is in our own hands.
"We have to get rid of the negative thoughts and go again."
Blackburn boss Gary Bowyer: "I thought we were terrific first half.
"Our football was good and the big man, Rudy Gestede, was unplayable. He took his goals ever so well.
"We always knew Birmingham would come and fight in the second half and that is exactly what they did, although we were disappointed with the two goals we conceded.
"But overall we have come away from home and scored four goals, which must be pleasing.
"We are now unbeaten in the last 10 games. It has been a very busy period for us and the quality of the squad shone through against Birmingham as we lost four players from last Friday.
"Everyone played their part and we now have to see what happens on Saturday."
- 17ReillyBooked at 70mins
- 37BlackettSubstituted forHancoxat 45'minutes
- 11LøvenkrandsSubstituted forGrayat 68'minutes
- 9MachedaBooked at 59mins
- 10HowardSubstituted forZigicat 29'minutesBooked at 88mins
- 5HanleyBooked at 74mins
- 32ConwaySubstituted forTaylorat 83'minutes
- 39GestedeSubstituted forVarneyat 59'minutes
- 7KingSubstituted forFeeneyat 75'minutes
- Mark Haywood
- Shots on Target
Second Half ends, Birmingham City 2, Blackburn Rovers 4.
Attempt blocked. Chris Burke (Birmingham City) left footed shot from the right side of the box is blocked. Assisted by Nikola Zigic with a headed pass.
Liam Feeney (Blackburn Rovers) wins a free kick in the defensive half.
Foul by Mitch Hancox (Birmingham City).
Attempt blocked. Nikola Zigic (Birmingham City) left footed shot from outside the box is blocked.
Attempt missed. Demarai Gray (Birmingham City) right footed shot from the left side of the box misses to the right.
Corner, Birmingham City. Conceded by Paul Robinson.
Attempt saved. Callum Reilly (Birmingham City) left footed shot from outside the box is saved in the bottom right corner. Assisted by Chris Burke.
Attempt blocked. Paul Caddis (Birmingham City) right footed shot from outside the box is blocked.
Nikola Zigic (Birmingham City) is shown the yellow card for a bad foul.
Grant Hanley (Blackburn Rovers) wins a free kick in the defensive half.
Foul by Nikola Zigic (Birmingham City).
Foul by Corry Evans (Blackburn Rovers).
Federico Macheda (Birmingham City) wins a free kick in the defensive half.
Delay over. They are ready to continue.
Delay in match Jason Lowe (Blackburn Rovers) because of an injury.
Jason Lowe (Blackburn Rovers) wins a free kick in the attacking half.
Foul by Callum Reilly (Birmingham City).
Goal! Birmingham City 2, Blackburn Rovers 4. Demarai Gray (Birmingham City) right footed shot from outside the box to the bottom left corner. Assisted by Federico Macheda.