Jonas Gutierrez inspired Newcastle to their first win in six matches at the expense of Birmingham at St Andrew's.
The Argentine winger set up both goals, with the first coming in the second minute when Peter Lovenkrands stole in at the near post to poke in.
Leon Best added a second after the break when he headed in Gutierrez's left-wing cross from close range.
Birmingham's Nikola Zigic forced a good low save from Steve Harper who was also alert to Roger Johnson's header.
The result moves Newcastle up from 10th to ninth but more importantly for Alan Pardew's men it puts them within striking range of a possible European spot.
For Birmingham, the defeat leaves them on the the fringes of the drop-zone and with a Carling Cup final date at the end of the month, they could do with going into that day without having to worry about a relegation dogfight.
Going into the match, two points on the pools coupon almost seemed a certainty. Blues had drawn 12 league matches this season, while Newcastle had drawn four of their last five and only 26 goals had been scored at St Andrew's this season - fewer than at any other Premier League ground.
So it came as a surprise when Newcastle took the lead after just 95 seconds of play, on a rain-soaked night in Birmingham.
Left-back Jose Enrique rocketed down the wing and delivered a cross that was cut out but only to Gutierrez, whose cross to the near post was anticipated and tucked away by Lovenkrands for his third in the league this season.
Birmingham responded well, with former Newcastle full-back Stephen Carr causing a problem on the right, while the influential midfield pairing of Seb Larsson and Craig Gardner were punching balls into the area in the hope that Zigic would be able to get his 6ft 7in frame on to one of them.
Blues' first effort in anger did come from a Larsson cross, but his ball fell to the slightly shorter Johnson, who headed wide at the far post.
A few moments later, Serbian Zigic proved he is not just a big lump to hit the ball up to as he swivelled in the area from 12 yards to force a fantastic low save from Harper.
The rain had eased off by the time the second half started but before the Birmingham XI could make the most of the better conditions, they conceded again.
Gutierrez was once more the provider as he crossed to the far post for Best to power in from about three yards.
Cameron Jerome was brought on for Obafemi Martins in the last 30 minutes after the former Magpie failed to make an impact in the match, although he did show a lot of enterprise.
Jerome was involved in Birmingham's next chance. He took away defenders as a right-sided corner was played in, only for Johnson to head straight at Harper.
And late in the match, Jerome scuffed a shot from David Bentley's low cross, summing up Birmingham's evening - good build-up but let down by poor execution.
Newcastle manager Alan Pardew: "I think it was evident that the players we have can fill the gap after Carroll.
"The pleasing thing is that the two strikers showed effort and commitment despite the pressure that is on them.
"We came into this game with momentum after our draws against Arsenal and Blackburn and it was really about getting the start right.
"We started faster and that made the difference and we also passed the ball well on a tricky surface."
Birmingham manager Alex McLeish: "We've had a fantastic month really in terms of results since the game against Manchester United at Old Trafford.
"There have been some inspired performances but tonight we looked a bit flat.
"To lose the first goal so easily as we did and so early goes against what we were like at the weekend (against Stoke) when the concentration levels were phenomenal.
"I think there was a bit of fatigue. One or two players looked a bit tired and I am not going to hammer the players after one performance like that."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.