The Board of Directors, keen to see a higher standard of football at the club, make further funds available to Fred Stewart to strengthen the side. They also decide to join the Southern Alliance, a strong competition for reserve sides, but in the event, the side selected for most matches is mainly made up of first team players. There are further personnel changes as Davy McDougall decides on a move to Newport County to become their player-manager, where he signs City goalkeeper Ted Husbands. Fred Stewart goes out and signs another series of seasoned professionals in the form of goalkeeper Jack Kneeshaw from Colne, defenders Tommy Doncaster from Barnsley, Henry Harvey (known as 'Kidder') from Wallsend, Reuben Croft from Portsmouth and Pat Cassidy from Bradford City. Forward Harry Keggans arrives from the same source. A local amatuer is signed on from the Roath Wednesdays club, one Fred Keenor. He eventually signs on full time during November 1912. City's first opponents of the season are Swansea Town, making their debut in the Southern League, and the result is 1-1. City then win a couple of games but Fred Stewart decides that the team still needs strengthening and signs Billy Devlin from Stockport County to play at centre forward. During the autumn City go on a run that brings forth 9 successive wins, but this ends when Luton Town beat City 2-0 at Kenilworth Road on Boxing Day. City bounce back with big wins over Llanelly by 5-0 , then Ton Pentre by 9-0, and this sets City well on the road to promotion. Still Fred Stewart is not entirely satisfied though, and he pays Newport County a £100 transfer fee to for their winger Andy Holt. He also brings in defender Colin McKechnie from Bradford City. These signings are able to be financed by the ever strengthening support for the club, and a new crowd record for Ninian Park is established on March 31st when table leaders Luton Town visit for a match that is seen by just over 20,000 spectators. City win the game 3-0. It is City's last home game of the season, but two further wins and a draw mean that City are Southern League Second Division Champions. In the F.A.Cup, City go to Merthyr in the 1st preliminary round, and not only win unexpectedly, but convincingly, by 5-1. Pontypridd then visit Ninian Park where in front of 12,000, City win 2-1. They also dispose of Llanelly and then Southern League First Division opponents in the form of Exeter City, by 5-1. The run is ended when Southend United visit Ninian Park on December 14th and win 3-0. In the Welsh Cup, City dispose of Ton Pentre and Bangor City before Swansea Town visit Ninian Park and win 4-2. It has been an outstanding season with the major objective achieved in the form of promotion to the Southern League First Division.
A City team group pictured sometime during the 1912-13 season.MANAGER: Fred Stewart
P. 24 W. 18 D. 5 L. 1 For 54 Ag. 15 Pts. 41 Posn. 1st (Prom.)
Names displayed in light green indicate a player making his debut.
| No. | Date | Opponents | Competition | V. | Res. | Goalscorers | Att. | 1. | 2. | 3. | 4. | 5. | 6. | 7. | 8. | 9. | 10. | 11. | |
| 1. | September 7 | Swansea T. | Southern League | A | 1-1 | D | Burton J. | 8,000 | J.Kneeshaw | R.Croft | R.Leah | H.Harvey | L.Saunders | W.Hardy | H.Tracey | J.Burton | H.Featherstone | H.Keggans | J.Evans |
| 2. | September 12 | Mid-Rhondda | Southern League | A | 1-0 | W | Keggans | 4,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | J.Burton | H.Featherstone | H.Keggans | J.Evans |
| 3. | September 14 | Newport Co. | Southern League | H | 2-0 | W | Tracey, Featherstone | 8,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | J.Burton | H.Featherstone | H.Keggans | J.Evans |
| 4. | September 21 | Ton Pentre | Southern League | A | 1-0 | W | Burton J. | 6,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | J.Burton | W.Douglas | H.Keggans | W.Gaughan |
| 5. | September 28 | Croydon Common | Southern League | H | 3-1 | W | Burton J. 2, Keggans | 7,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | J.Burton | W.Devlin | H.Keggans | J.Evans |
| 6. | October 3 | Millwall | Southern Alliance | A | 3-2 | W | Burton J., Evans, Devlin | J.Kneeshaw | T.Doncaster | R.Leah | T.Abley | P.Cassidy | W.Hardy | H.Tracey | J.Burton | W.Devlin | H.Keggans | J.Evans | |
| 7. | October 5 | Treharris Ath. | Southern League | A | 2-0 | W | Keggans, Devlin | 2,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | J.Burton | W.Devlin | H.Keggans | J.Evans |
| 8. | October 12 | Merthyr T. | FA Cup (Q1) | A | 5-1 | W | Harvey, Burton J., Devlin 3 | 11,500 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | J.Burton | W.Devlin | H.Keggans | J.Evans |
| 9. | October 19 | Mardy | Southern League | H | 5-2 | W | Burton G., Burton J., Cassidy, Evans, Devlin | 6,500 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | T.Abley | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans |
| 10. | October 23 | Brighton & H.A. | Southern Alliance | A | 1-4 | L | Evans | W.Douglas | G.Latham | T.Doncaster | H.Harvey | P.Cassidy | T.Abley | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans | |
| 11. | November 2 | Pontypridd | FA Cup (Q2) | H | 2-1 | W | Burton G., Burton J. | 12,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | L.Saunders | W.Hardy | H.Tracey | G.Burton | H.Featherstone | J.Burton | W.Gaughan |
| 12. | November 9 | Croydon Common | Southern League | A | 2-1 | W | Burton G. Evans | 6,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | H.Featherstone | J.Burton | J.Evans |
| 13. | November 12 | Southampton | Southern Alliance | H | 1-2 | L | Burton J. | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | H.Featherstone | J.Burton | J.Evans | |
| 14. | November 16 | Llanelly | FA Cup (Q3) | A | 4-1 | W | Burton G., Tracey, Evans, Gough (og) | 4,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans |
| 15. | November 20 | Brentford | Southern Alliance | H | 4-2 | W | Burton G., Tracey, Featherstone, Hickleston (og) | .Lewis | T.Doncaster | R.Croft | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | H.Featherstone | J.Burton | J.Evans | |
| 16. | November 30 | Exeter C. | FA Cup (Q4) | H | 5-1 | W | Harvey, Burton G., Burton J., Devlin 2 | 14,000 | W.Douglas | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans |
| 17. | December 7 | Treharris Ath. | Southern League | H | 2-1 | W | Tracey, Cassidy | 8,000 | W.Douglas | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans |
| 18. | December 11 | Southampton | Southern Alliance | A | 1-3 | L | Devlin | 500 | W.Douglas | T.Doncaster | R.Leah | T.Abley | H.Featherstone | W.Hardy | H.Tracey | G.Burton | W.Devlin | J.Burton | W.Gaughan |
| 19. | December 14 | Southend Utd. | FA Cup (Q5) | A | 0-3 | L | 7,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans | |
| 20. | December 21 | Southend Utd. | Southern League | H | 1-0 | W | Evans | 8,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans |
| 21. | December 25 | Pontypridd | Southern League | H | 1-1 | D | Featherstone | 11,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | H.Featherstone | J.Burton | J.Evans |
| 22. | December 26 | Luton T. | Southern League | A | 0-2 | L | 6,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | H.Featherstone | J.Burton | J.Evans | |
| 23. | January 1 | Llanelly | Southern League | H | 5-0 | W | Burton J. 2, Featherstone 2, Devlin | 3,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | H.Featherstone | W.Devlin | J.Burton | J.Evans |
| 24. | January 4 | Ton Pentre | Welsh Cup (3) | H | 4-2 | W | Burton G., Douglas 2, Featherstone | 2,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | G.Latham | W.Hardy | J.Bennett | H.Featherstone | W.Douglas | G.Burton | W.Gaughan |
| 25. | January 20 | Ton Pentre | Southern League | H | 9-0 | W | Tracey 2, Burton J., Cassidy 2, Devlin 3, Evans | 3,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | H.Featherstone | W.Devlin | J.Burton | J.Evans |
| 26. | January 25 | Bangor C. | Welsh Cup (4) | A | 4-0 | W | Burton J., Featherstone, Cassidy, Devlin | 3,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | H.Featherstone | W.Devlin | J.Burton | J.Evans |
| 27. | February 1 | Portsmouth | Southern Alliance | H | 1-1 | D | Featherstone | 3,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | L.Newton | W.Hardy | H.Tracey | H.Featherstone | W.Devlin | J.Burton | J.Evans |
| 28. | February 5 | Croydon Common | Southern Alliance | A | 0-3 | L | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | G.Latham | W.Hardy | H.Tracey | G.Burton | H.Featherstone | L.Nash | J.Evans | ||
| 29. | February 8 | Newport Co. | Southern League | A | 3-1 | W | Burton G., Cassidy, Tracey | 8,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | H.Featherstone | W.Devlin | G.Burton | J.Evans |
| 30. | February 12 | Aberdare Ath. | Southern League | H | 3-0 | W | Harvey, Tracey, Devlin | 4,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | H.Featherstone | W.Devlin | J.Burton | J.Evans |
| 31. | February 15 | Swansea T. | Welsh Cup (5) | H | 2-4 | L | Burton J., Cassidy | 12,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | H.Featherstone | W.Devlin | J.Burton | J.Evans |
| 32. | February 22 | Southend Utd. | Southern League | A | 1-1 | D | Burton G. | 7,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | J.Bennett | G.Burton | J.Clarke | J.Burton | H.Tracey |
| 33. | February 26 | Brighton & H.A. | Southern Alliance | H | 0-1 | L | 3,500 | J.Kneeshaw | T.Doncaster | R.Leah | C.McKechnie | T.Abley | W.Hardy | J.Bennett | G.Burton | J.Clarke | J.Burton | W.Gaughan | |
| 34. | March 1 | Mid Rhondda | Southern League | H | 1-0 | W | Burton G. | 6,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | J.Clarke | J.Burton | J.Evans |
| 35. | March 8 | Mardy | Southern League | A | 2-1 | W | Burton G., Clarke | 3,000 | J.Kneeshaw | T.Doncaster | G.Latham | C.McKechnie | P.Cassidy | W.Hardy | A.Holt | G.Burton | J.Clarke | J.Burton | J.Evans |
| 36. | March 12 | Croydon Common | Southern Alliance | H | 1-2 | L | Holt | 5,000 | J.Kneeshaw | T.Doncaster | R.Croft | T.Abley | L.Newton | C.McKechnie | A.Holt | G.Burton | W.Douglas | J.Clarke | J.Evans |
| 37. | March 15 | Swansea T. | Southern League | H | 0-0 | D | 10,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | T.Abley | A.Holt | G.Burton | W.Devlin | J.Clarke | J.Evans | |
| 38. | March 21 | Luton T. | Southern League | H | 3-0 | W | Burton J. 2, Burton G. | 22,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans |
| 39. | March 22 | Southend Utd. | Southern Alliance | H | 1-1 | D | Burton J. | J.Kneeshaw | T.Doncaster | R.Leah | G.Burton | G.Latham | C.McKechnie | H.Tracey | J.Clarke | W.Devlin | J.Burton | J.Evans | |
| 40. | March 24 | Pontypridd | Southern League | A | 1-1 | D | Hardy | 7,500 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | J.Bennett | G.Burton | W.Devlin | J.Burton | J.Evans |
| 41. | March 29 | Llanelly | Southern League | A | 2-0 | W | Burton J., Devlin | 1,500 | J.Kneeshaw | G.Latham | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | G.Burton | W.Devlin | J.Burton | J.Evans |
| 42. | April 5 | Aberdare Ath. | Southern League | A | 3-2 | W | Devlin, Evans, Burton G. | 2,000 | J.Kneeshaw | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | J.Burton | W.Devlin | G.Burton | J.Evans |
| 43. | April 9 | Millwall | Southern Alliance | H | 3-2 | W | Tracey 2, Clarke | W.Douglas | T.Doncaster | R.Leah | H.Harvey | P.Cassidy | W.Hardy | J.Bennett | H.Tracey | J.Clarke | J.Burton | J.Evans | |
| 44. | April 12 | Southend Utd. | Southern Alliance | A | 0-1 | L | J.Kneeshaw | T.Doncaster | R.Croft | H.Harvey | G.Latham | W.Hardy | J.Bennett | H.Tracey | J.Clarke | J.Burton | J.Evans | ||
| 45. | April 14 | Brentford | Southern Alliance | A | 2-4 | L | Bennett, Evans | W.Douglas | T.Doncaster | R.Croft | H.Harvey | P.Cassidy | W.Hardy | J.Bennett | H.Tracey | J.Clarke | J.Burton | J.Evans | |
| 46. | April 19 | Luton T. | Southern Alliance | A | 0-2 | L | .Lewis | T.Doncaster | R.Croft | H.Harvey | G.Latham | W.Hardy | H.Tracey | J.Clarke | W.Devlin | J.Burton | J.Evans | ||
| 47. | April 23 | Portsmouth | Southern Alliance | A | 1-3 | L | Devlin | 2,000 | W.Douglas | T.Doncaster | R.Croft | H.Harvey | G.Latham | W.Hardy | H.Tracey | J.Clarke | W.Devlin | J.Burton | J.Evans |
| 48. | April 26 | Luton T. | Southern Alliance | H | 5-2 | W | Devlin 2, Burton G. 2, Hardy | J.Kneeshaw | T.Doncaster | R.Croft | H.Harvey | P.Cassidy | W.Hardy | H.Tracey | J.Clarke | W.Devlin | G.Burton | J.Evans |
The following matches were also played during the season.
| Date | Match Details | Opponents | v. | Res | Goalscorers | |
| September 4 | Friendly | Treharris Ath. | H | 5-0 | W | Douglas 2, Keggans 2 |
| November 11 | Friendly | Cwm Albion | A | 1-2 | L | Gorman |
| March 25 | Friendly | Newport Co. | A | 1-1 | D | Evans J. |
| April 2 | Friendly | Bridgend YMCA | A | 9-0 | W | Douglas 3, Evans D. 2, Evans J., Newton, Bennett, Keenor |
| April 28 | Friendly | Pontypridd | A | 1-1 | D | Douglas |
| April 30 | Friendly | Mid-Rhondda | A | 1-1 | D | Burton G. |