NEWCASTLE 4 BIRMINGHAM 0
26. Karl Darlow
8. Vurnon Anita
6. Jamaal Lascelles
2. Ciaran Clark
3. Paul Dummett
11. Matt Ritchie
12. Jonjo Shelvey
14. Isaac Hayden 82'
20. Yoan Gouffran 70'
15. Mohamed Diame
9. Dwight Gayle 79'
Subs
7. Achraf Lazaar 82'
18. Chancel Mbemba
22. DeAndre Yedlin
24. Cheick Tiote
28. Matz Sels
30. Christian Atsu 70'
45. Aleksandar Mitrovic
Dwight Gayle netted a hat-trick as Newcastle moved back to the top of the Sky Bet Championship in style by brushing aside play-off hopefuls Birmingham 4-0 at St James' Park.
The Magpies never looked back after hitting the half-time break with a two-goal cushion courtesy of Gayle's double in front of the Gallowgate.
And the Championship's leading scorer took his tally to 16 by completing his treble with 12 minutes to go to end Newcastle's recent three-game run without a victory.
By then Yoan Gouffran had already added a third seconds after the break to ensure Rafael Benitez's men moved a point clear of Brighton again.
Birmingham struggled to come to terms with Newcastle, who fielded Jonjo Shelvey and Paul Dummett after they had the red cards they received at Nottingham Forest eight days earlier overturned.
Despite that decision Newcastle's players were keen to put on a show after feeling aggrieved that they had lost at the City Ground having been forced to play a lot of the game with nine men - allowing Brighton to hit top spot by defeating Leeds on Friday evening.
Put on a show was exactly what Newcastle did in the first half when the only surprise was that Birmingham, who have now lost five consecutive away league games on Tyneside for the first time, had not conceded more than two.
Gayle had already been denied by goalkeeper Tomasz Kuszczak and Isaac Hayden was inches away from finding the top corner before the first arrived in the 18th minute.
Newcastle's leading marksman worked his way free of his marker to cushion a tidy header inside the bottom corner when he got on the end of Mohamed Diame's perfect centre.
Six minutes later Gayle added a second. After a lovely move down the right involving several players, Hayden charged into the area and centred.
After a fortunate deflection, Gayle controlled in the six-yard box before slotting inside the bottom corner and beyond the goalkeeper.
Before the break Gouffran, Matt Ritchie and Diame all went close, while Birmingham struggled to make any inroads towards Karl Darlow's net at the opposite end.
And it did not take long for Newcastle to add the third after the restart; 70 seconds in fact.
Shelvey's free-kick was poorly dealt with and Gouffran was on hand to convert from 12 yards, effectively putting the game to bed there and then.
Gayle came within inches of grabbing his hat-trick just after the hour when Kuszczak turned his effort behind following an incisive first-time pass from the impressive Diame.
Birmingham, who started the day fifth, did record an effort with 20 minutes to go when substitute Lukas Jutkiewicz headed over at the back post, which raised an ironic cheer from the travelling fans.
Just when it seemed Newcastle were happy to slow things down in the closing stages, Gayle pounced to turn in Shelvey's pass in the 78th minute to wrap up a comprehensive win.