A City under-18s side - containing seven under-15 and 16 players - were beaten 3-0 at home to EFL Youth Alliance North East league-leaders Doncaster Rovers.
The young Bantams - whose starting 11 contained four under-16s - put up a valiant effort but ultimately had their six-game unbeaten run halted.
The first goal of the game went to the visitors - through Junior Smith - inside the opening five minutes.
Rovers' attacker Owan Derrett was gifted possession before playing it into Smith, who opened up his body and slotted home.
Despite City creating a couple of chances through Raj Palit and Jonny White, Doncaster added another.
Jack Watson was quickest to react from an Elliot Walker cross and flicked it in - on the half-hour mark.
Mark Trueman’s men were close to pulling one back after the break, courtesy of Wade Ripley.
The attacker flashed the ball across goal, but it came to no avail as it rolled out of play - in the 55th minute.
With pressure building on the Bantams, the away side made it three - four minutes later.
Second-half substitute Marius Conradi broke away and smashed home after a calculated through ball from Lirak Hasani.
The young Bantams pushed for a consolation, late on, but could not convert as Doncaster came away with all three points.
CITY: Tom Donaghy; Hayden Smethurst (c), Luke Harrop (Bobby Pointon 80'), Jorge Sikora, Harvey Rowe; Kian Scales (Sonny Whittingham 70'), Olivier Sukiennicki, Raj Palit; Yahaya Tunkara (Frankie Sinfield 75'), Jonny White, Wade Ripley. Subs (not used): Darryl Ombang (GK).
DONCASTER: Ben Bottomley; Elliott Walker (Josh Clemitson), Ben Blythe (C), Nathan Dimou (Max Jemson), Lewis Cunningham, Lirak Hasani (Luca Nelson), Charlie Bell, Liam Ravenhill, Owan Derrett, Jack Watson (Marius Conradi), Junior Smith. Subs (not used): Kian Johnson.
GOALS: Junior Smith (5'), Jack Watson (30'), Marius Conradi (59').