The Bluebirds began the game strongly and took the lead after just seven minutes. Theo Wharton's initial shot was well saved by Jojo Woolacott, but the Robins 'keeper was unable to stop forward Eli Phipps from firing in the rebound.
Kevin Nicholson's side bettered their opposition throughout the match but were pegged back after 70 minutes. Shaun McCoulsky managing to bundle the ball home at close range after a dangerous set piece evaded the City defence.
Both sides pushed for a winner during the remaining twenty minutes, and subsequent extra time period, with the match finally settled in the final moments of the additional time. Matty Kennedy's free kick was exquisitely controlled in the area by Thomas James, chesting the ball before crossing for his central defensive partner, Ashley Baker to head home the all-important winning goal.
FINAL SCORE: CARDIFF CITY 2-1 BRISTOL CITY AET (Phipps 7', Baker 120'; McCoulsky 70')
Cardiff City: Wilson, Barnum-Bobb, Abbruzzese, Patten, Baker, James, Kennedy, Wharton (Southam, 68), Phipps (Noor, 90), Veale, Roche. Subs Not Used: Watkins, Wakeman, Burridge.