By Anthony Marshall, at St. Andrews
Newcastle 2 (Lovenkrands 2; Best 50)
Both front men struck early in each period to give the Magpies a massive confidence boost, and the victory was no more than they deserved for another assured defensive display while looking dangerous on the counter-attack.
Best and Cheick Tiote could have added to the scoreline, and Birmingham's chances were rare with the hosts rarely providing any sort of threat in the second half.
With many people expecting a dull encounter between two low-scoring sides, they got an opening spell which completely defied that logic.
On a difficult, slippy surface made all the more dangerous by heavy first half rain, Newcastle opened the scoring after just 92 seconds.
And it was perfect for Lovenkrands, who nipped ahead of his marker to poke home past Ben Foster.
Birmingham striker Obafemi Martins, lining up against his former employers, made a lively start to proceedings with a couple of neat lay-offs.
And had his touch been quite as heavy in the 14th minute then the Nigerian would have been in behind the visiting defence, but Danny Simpson was on hand to avert the danger.
The hosts went close minutes later, defender Roger Johnson sending a downward header just the wrong side of the upright having connected with Sebastian Larsson's deep free-kick.
And they continued to press, with only a magnificent fingertip save from Steve Harper preventing Nikola Zigic from levelling things up. Enrique was robbed of possession in a bad area by Martins, and as Barry Ferguson swept the ball on to Zigic, the beanpole striker's angled shot - destined for the far corner - was turned away by Harper.
Chances kept falling to Birmingham and midfielder Craig Gardner was presented with a great one on 39 minutes. After Mike Williamson misjudged the flight of a long ball, Larsson pounced and made his way into the area, before teeing up Gardner from 20 yards.
The former Aston Villa man's drive had power but was wayward, sailing high and wide when he should have at least hit the target.
Newcastle were not content with just a single goal led, however, and the impressive Leon Best headed Enrique's cross over shortly before sending a low shot wide.
If the Magpies' start to the first half was quick, it took a little longer for them to get going in the second - but only just.
Merely five minutes had elapsed after the restart when Barton fed Gutierrez wide on the left. The Argentinian international turned Larsson inside out before sending another superb cross to the far post where Best was left with the simplest of tasks to head home.
David Bentley curled over from the edge of the box for Birmingham in the 63rd minute, but that was a rare chance for the hosts, who by this point looked shot of confidence and devoid of any creativity.
Newcastle weren't done at two and sensed their could be even more goals for them in this game. Inspired by his stunner against Arsenal 10 days ago, Cheick Tiote tried his luck from 25 yards only to Blues keeper Foster pluck it out of the top corner.
Birmingham threw on former Sunderland striker Kevin Phillips for the last 14 minutes, hoping the veteran would inspire them, but it was a defender who almost halved the deficit.
Roger Johnson met Bentley's corner with a thumping, unmarked header, but somehow put his effort straight into the midriff of Harper, when anywhere else would have surely resulted in a goal.
But the visitors held firm for a second successive clean sheet, making it just one defeat from eight league games for Alan Pardew's side.
Birmingham (4-4-2): Ben Foster; Stephen Carr (c), Roger Johnson, Martin Jiranek (David Murphy 73), Liam Ridgewell; Sebastian Larsson (Kevin Phillips 76), Craig Gardner, Barry Ferguson, David Bentley; Obafemi Martins (Cameron Jerome 58), Nikola Zigic
Subs not used: Colin Doyle, Lee Bowyer, Keith Fahey, Jean Beausejour
Newcastle (4-4-2): Steve Harper; Danny Simpson, Mike Williamson, Fabricio Coloccini, Jose Enrique; Joey Barton, Cheick Tiote, Kevin Nolan (c), Jonas Gutierrez (Sol Campbell 87); Leon Best (Danny Guthrie 75), Peter Lovenkrands (Nile Ranger 65)
Subs not used: Tim Krul, James Perch, Shane Ferguson, Shefki Kuqi
Referee: Lee Mason
Attendance: 28, 270