Two goals from Milan Baros and a breathtaking strike from Gary Cahill earned Aston Villa victory over troubled rivals Birmingham.
Villa defender Cahill scored his first goal for the club
Villa led when Baros was left unmarked to lash in Aaron Hughes' cross from close range but Birmingham drew level through Chris Sutton's low drive.
The hosts went back in front on 56 minutes when Cahill leapt and sent a spectacular volley over Maik Taylor.
And Baros wrapped up victory with a crisp finish from a difficult angle.
The result puts Villa 10 points clear of the drop zone but leaves Birmingham, who dropped into the bottom three on Saturday after Portsmouth's win, three points from safety with four games remaining.
The Blues suffered another blow before the kick-off when Matthew Upson ruptured his Achilles tendon in the warm-up.
But Steve Bruce's side made a positive start, with Sutton and Emile Heskey looking to outmuscle Aston Villa's young centre-backs Cahill and Liam Ridgewell.
Thomas Sorensen was called into action inside four minutes, saving from Nicky Butt, but the keeper did not help ease the nerves of his defence with several terrible clearances early on.
However, as soon as Villa went on the attack for the first time, they discovered the visitors' backline was equally suspect.
To be fair to Birmingham, the linesman should have flagged when James Milner caught Matthew Sadler in the face with a high boot.
Milner then fed Hughes, whose cross evaded everyone except the unmarked Baros, who, from two yards out, had time to pull the ball down before finishing.
Bruce looked on exasperated and matters got worse for the Blues boss when David Dunn, who had looked sharp, limped off to be replaced by Mikael Forssell.
However, Villa were to suffer an injury blow of their own when Steven Davis came off to be replaced by Craig Gardner and moments after, Birmingham drew level.
Sutton and Heskey's menace in the box proved decisive, the latter winning a header which dropped for his strike partner to drive in through a crowd of players.
But it was another defensive lapse which eventually led to Villa's second, nine minutes after the restart.
Olivier Tebily's weak header hit Kevin Phillips in the box and he eventually headed towards Cahill.
The 20-year-old, in only his fourth appearance for the club, launched himself into the air and volleyed over Taylor and into the opposite corner.
The youngster was booked for celebrating his first goal for Villa with the fans, but you could hardly blame him for his over-exuberance.
Birmingham immediately went in search of another equaliser, and Sorensen kept his side in front when he got down quickly to smother Forssell's snapshot.
But with the visitors dominating, Villa struck on the counter-attack, Baros beginning and ending the move which ended Birmingham's hopes of a recovery.
Aston Villa manager David O'Leary:
"I have never looked at the relegation zone. I have kept my eyes on the teams we have a chance of catching above us.
"If we defended set plays with our two young centre backs in the second half I thought we would go on from there.
"I'm delighted for the players and the supporters. We were worthy winners."
Birmingham boss Steve Bruce:
"We're still in there with a chance but we needed to beat Villa to keep the pressure on Portsmouth.
"The big turning points went against us and we didn't get what we deserved.
"We live to fight another day and we'll give it everything we can. Portsmouth are in the driving seat but all we have to do is win more games than them."
Aston Villa: Sorensen, Hughes, Ridgewell, Cahill, Samuel, Milner (Agbonlahor 85), McCann, Davis (Gardner 24), Barry, Baros, Phillips (Angel 59).
Subs Not Used: Taylor, De la Cruz.
Booked: Baros, Cahill, McCann, Barry.
Goals: Baros 10, Cahill 56, Baros 78.
Birmingham: Maik Taylor, Tebily, Cunningham (Lazaridis 79), Sadler, Martin Taylor, Pennant, Butt, Johnson, Dunn (Forssell 17), Heskey, Sutton.
Subs Not Used: Vaesen, Izzet, Bruce.
Booked: Johnson, Tebily, Butt.
Goals: Sutton 25.
Ref: G Poll (Hertfordshire).