The two yellow cards conceded by Edinburgh in the helter-skelter final few minutes of their Round 18 Magners League game against Leinster in Dublin saw them fall from grace at the top of the Specsavers Fairplay League, leaving Blues the outright winners.
For the second season in a row a Welsh region has won the £10,000 grant to spend on a youth development programme. The Scarlets were the top side in 2008/09, with an exemplary three yellow cards for a mere three points, while Munster topped the league in its inaugural season of 2007/08 with seven.
"This is fantastic news for the Blues and the money will help us to enhance our already comprehensive youth programme within our region," said Blues chief executive Rob Norster.
"There are now 65 clubs within the five unitary authorities within the Cardiff Blues region and our home grown talent includes players of the calibre of British & Irish Lions prop Gethin Jenkins, Wales lock Bradley Davies and new Wales flanker Sam Warburton.
"While we were disappointed to miss out on the Play-Offs, this award gives us something to feel proud of for the season."
Nick King, chairman for Specsavers in Wales, said: "I'm delighted that the Blues have become the second Welsh team in two years to boast exemplary conduct on the pitch. Specsavers' sponsorship of the Magners League is all about supporting the referees, ensuring that they see clearly and maintain the spirit of gamesmanship.
"With international rugby season just around the corner, we hope that the Blues' achievement highlights the importance of fair play in Welsh rugby and encourages players to keep their conduct clean on-field."