Three first-half goals saw Cardiff City end the weekend as leaders of the Championship.
Captain Mark Hudson opened the scoring for the Bluebirds, before Craig Conway and Rob Earnshaw added further goals before the break.
Transfer-linked Nick Maynard pulled a goal back for visiting City with eight minutes remaining when he turned in a cross from Jamal Campbell-Ryce.
Cardiff play host to Brighton & Hove Albion on Wednesday, August 17 while Bristol City travel to Leicester City on the same evening.