United were facing an uphill battle at the break with first-half goals from Veatriki Sarri, Batcheba Louis and Lilly Crosthwaite putting the hosts in a comfortable position.
Newcastle did manage to find the back of the net twice in the second half through Jasmine McQuade and a first goal of the season for Beth Lumsden.
However, Oceana Hurtre added a fourth for the Blues in the second half to ensure the three points would stay in the Midlands.
Before the game kicked off, a minute's silence was impeccably observed by both sets of teams and supporters, in honour of Matt Beard and Maddy Cusack.
Birmingham made their intentions clear from the outset as they tested Femke Liefting from close range after just minutes, but the young keeper saved well with her legs.
United looked to have carved an opening just two minutes later when Emily Murphy ran from her own half unchallenged to the Birmingham box, but a last-ditch Neve Herron slide tackle stopped her from getting a strike off.
However, it was the hosts who struck first when they won the ball high up the pitch from Newcastle before Sarri struck from 25 yards out and saw her effort squirm past Liefting.
The Blues doubled their advantage five minutes later when a low cross from Rebecca McKenna wasn't fully cleared by United, allowing Louis to volley home from the edge of the area into the bottom left corner.
It looked as though the Lasses were about to find a way back into the game when Molly Pike picked out the unmarked Demi Stokes at the back post, but despite her ferocious effort beating Lucy Thomas, McKenna was backing her up to prevent a certain goal.
United were looking as if they'd gone up a gear after Stokes' effort as Murphy showed good strength down the right-hand side and picked out Oona Sevenius, whose first-time touch teed up Pike nicely, but her effort was straight down the throat of Thomas from inside the area.
Despite Becky Langley's side appearing to finish the first half as the stronger side, they were hit with a sucker punch seven minutes before the break. A corner wasn't sufficiently cleared, allowing the hosts to recycle the ball.
The resulting second ball into the box found Crosthwaite, who made no mistake in thumping home her effort into the far corner and past Liefting.
Newcastle's afternoon almost got worse 45 seconds into the second half when a short Deanna Cooper pass gave Crosthwaite the chance to cross into Sarri, who found the back of the net but was quickly flagged offside.
As the game ticked over into the hour mark, Newcastle made their mark on the match by clawing a goal back. A well-won header by Charlotte Wardlaw set Sevenius free down the left.
The Finland international did well to pick out McQuade, who, much like last week against Sheffield United Women, made a late run into the box before sending an emphatic header over the head of Thomas.
While Newcastle got themselves back in the game, Birmingham restored their lead when Lois Joel's pass went straight to Hurtre, who finished first time into an empty net.
Lumsden managed to get on the scoresheet for the first time this season after she pounced on Murphy's strike, which cannoned off the crossbar, allowing United's number 26 to nip in in front of the Birmingham defenders and fire home.
Newcastle United Women: Femke Liefting, Charlotte Wardlaw, Deanna Cooper (Malgorzata Grec 76), Aoife Mannion, Jordan Nobbs (Jasmine McQuade 45), Morgan Gautrat (Lois Joel 66), Demi Stokes (c), Lia Cataldo (Jorja Fox 76), Molly Pike, Emily Murphy, Oona Sevenius (Beth Lumsden 76)
Subs not used: Claudia Moan, Shania Hayles, Freya Gregory
