Cameron Jerome ended a three-game run without a goal to hand Cardiff the half-time initiative against Coca-Cola Championship rivals Hull.
The 19-year-old striker bagged his 15th league goal of the season, in the 22nd minute, after Darren Purse had headed into his path.
A left-wing raid from Jason Koumas resulted in a pin-point centre which Purse nodded back across goal for Jerome to poke into an empty net.
A lacklustre opening burst into life in the 14 minute when on-loan West Brom midfielder Koumas picked the ball up midway inside the Hull half and ran at the Tigers' defence.
His jinking run resulted in a trio of corner-kicks for the Bluebirds - all taken by the Wales international - from which former Baggies team-mate Purse put the third over the crossbar.
Steven Thompson, back in the starting line-up after recovering from surgery to a badly-cut finger, went close from the edge of the area, but his curling effort sailed inches wide of Boaz Myhill's top corner.
But it was not long before the Bluebirds' pressure eventually told and Jerome poked the ball home midway through the half to round off a flowing move by Dave Jones' side.
Hull responded well to the setback and had the ball in the net themselves almost immediately from the restart, but the effort was ruled out for offside.
Jon Parkin should have notched his fifth Tigers goal since joining from League Two side Macclesfield in January, but he diverted Kevin Ellison's 26th-minute cross on to the post from just six yards out.
A low shot from Jerome forced Myhill into his first action of the afternoon when the stopper reacted quickly to smother an angled drive through a crowded penalty area.
Cardiff goalkeeper Neil Alexander tipped Ellison's header around the post on the stroke of half-time, but the Bluebirds defended the resulting corner to go into the break ahead.
Teams:
Cardiff Alexander, Barker, Purse, Cox, Scimeca, Whitley,Ardley, Koumas, Ledley, Thompson, Jerome (Weston 83).
Subs Not Used: Margetson, Boland, Mulryne, Ndumbu-Nsungu.
Booked: Ledley.
Goals: Jerome 22.
Hull Myhill, Thelwell, Cort, Delaney, Rogers,Paynter (Duffy 59), Andrews, Noble, Ellison (Elliott 63),Parkin, Fagan (Green 63).
Subs Not Used: Duke, Stockdale.
Booked: Andrews.
Att: 11,047
Ref: B Curson (Leicestershire).