Captain Sam Bowen and his under-18 Bluebirds slipped to a harsh defeat in their Professional Development League match against Sheffield United at the Steelphalt Academy in Yorkshire.
Bowen was desperately close to an equaliser when he hit both post twice in the space of a few seconds just before the hour. His free-kick came back off a post and his follow-up effort seconds later struck the other post.
Substitute Robin Colwill fired against the bar four minutes from time and left Cardiff feeling remarkably frustrated after controlling much of the play.
An away win would have lifted Cardiff City into top spot in the Southern Division ahead of current leaders Ipswich Town.
Jake Young’s header after 20 minutes put the Blades in front before Cardiff levelled the score from a Dan Griffiths penalty after half an hour.
The Bluebirds found the net following a flowing attack, but the referee had blown before the ball went in and awarded a spot-kick.
It was 1-1 at half-time before Tom Wilson’s towering header from Frankie Maguire’s corner 10 minutes from time clinched the points during a match in which Sheffield United had to hang on at times.
Goalkeeper Sam Kelly made some excellent saves for United, while Cardiff’s George Ratcliffe pulled off a superb save to claw away a Scott header before getting up to hold a strong effort from Nickseon Gomis from the resulting corner.
Sheffield United: S Kelly, Williamson, Foulstone, Wilson,
Weaver, Gomis, Antwin (Ackroyd 66), Broadbent, Young (Gaxha 81), Ompreon
(Maguire 58), Scott. Subs not used: Amissah, Hackford.
Cardiff City under-18: George Ratcliffe, Ryan Kavanagh (Taylor Jones 64), Ben Margetson, Joel Bagan, Sam Parsons (Rubin Colwill 48), Keenan Patten, Ntazana Mayembe (Siyabonga Ligendza 80), Harry Pinchard, Sam Bowen (capt), Kieron Evans, Dan Griffiths. Subs: Jordan Duffey (gk), Smith.