Head Coach Danny Wilson praised the performances of Academy products Jarrod Evans and Ethan Lewis as they impressed in difficult derby conditions.
Wales Under-20 fly half Evans, 19, was handed his first-ever Guinness PRO12 start against the Ospreys and produced an assured display with two penalties putting Cardiff Blues up on the hour.
Hooker Ethan Lewis, 21, also performed admirably in swirling winds as a second half replacement for Kristian Dacey.
Wilson highlighted the display of both after the game but insisted they would need to be given time to put their stamp on the senior side.
“It was a great experience for Jarrod,” he said. “There is no tougher venue to come to and play in a derby.
“That game will stand him in good stead; there are areas of his performance to improve on, but generally he was good. His first half defensive display in particular was excellent.
“Some of our attack was credit to him and our attacking shape was better in the second half.
“I am pleased for Jarrod; it’s important for us to build for the future with players like him.
“I thought Ethan Lewis did well for us too,” he added. “They (Ospreys) bought a slightly different lineout defence that we hadn’t seen in the second half, but credit to Ethan because he did well in those conditions. He threw well and James Down called the relevant calls to help him.
“Ethan is an example of another young home-grown Cardiff Blues player who we now need to give exposure and be patient with so he will come through for us.”