NEWCASTLE UTD 3 BIRMINGHAM 1
28. Matz Sels
22. DeAndre Yedlin 75'
5. Grant Hanley
37. Stuart Findlay
7. Achraf Lazaar
12. Jonjo Shelvey
24. Cheick Tiote 82'
11. Matt Ritchie
36. Yasin Ben El-Mhanni 70'
35. Daniel Barlaser
20. Yoan Gouffran
Subs
3. Paul Dummett
4. Jack Colback 82'
6. Jamaal Lascelles
14. Isaac Hayden 75'
17. Ayoze Perez 70'
21. Rob Elliot
33. Daryl Murphy
Jonjo Shelvey returned from his five-game ban to mastermind Newcastle's progression to the FA Cup fourth round with a 3-1 replay victory over Birmingham.
The England international midfielder, who was convicted of using racially aggravated language towards Wolves midfielder Romain Saiss last month despite his denials, reminded manager Rafael Benitez of what he had been missing as the Magpies booked a trip to Sky Bet League One side Oxford in the next round.
Matt Ritchie's early penalty and Yoan Gouffran's sixth goal of the season did the damage in front of a crowd of 34,896 as talk of a brewing transfer battle between Benitez and owner Mike Ashley was forgotten, although David Cotterill's late strike set up a tense conclusion before Ritchie struck vert late on.
With promotion back to the Premier League the overriding priority, Spaniard Benitez shuffled his depleted pack to the extent that he handed senior debuts to youngsters Dan Barlaser on his 20th birthday, Stuart Findlay and Yasin Ben El-Mhanni, whose claims to fame include working as a body double for Cristiano Ronaldo and Neymar.
But it was Shelvey who stepped back into the limelight as his ninth-minute through-ball allowed Gouffran to escape from City skipper Paul Robinson and attempt to round keeper Adam Legzdins.
Referee Lee Probert pointed immediately to the spot after Gouffran was bundled to the ground and Ritchie converted with the minimum of fuss.
Shelvey himself tested Legzdins from distance with a dipping effort, but the keeper needed the help of a post to keep out Gouffran's audacious flick from Achraf Lazaar's 29th-minute cross.
However, the Frenchman increased the Magpies' lead within six minutes when he controlled Shelvey's free-kick with his back to goal before spinning and dispatching the ball into the bottom corner.
Ritchie would have had his second of the night three minutes before the break had his shot not come back off the inside of a post, but the lead was no more than Newcastle deserved despite Cotterill going close on three occasions during an early flurry from the visitors.
The Magpies repeatedly hit Birmingham on the counter after the break, but failed to take their chances and were made to pay when Cotterill's mis-hit 71st-minute shot eluded keeper Matz Sels.
Substitute Lukas Jutkiewicz might have levelled five minutes later but headed over, and Ritchie finally ended the tie in stoppage-time with Shelvey once again the architect.