Crystal Palace lead Cardiff 1-0 at half time through a 13th-minute goal by Wilfried Zaha at Selhurst Park.
Liam Lawrence had the first effort on goal with a right-footed shot from 20 yards, which was saved by Lewis Price.
Palace took the lead on 13 minutes when Darren Ambrose fed Wilfried Zaha from the right wing, before the forward finished from 18 yards to make it 1-0.
Joe Mason had the chance to equalise for Cardiff, but his header from 12 yards was easily caught by Price.
Moments later, Glenn Murray's header was saved by David Marshall to deny the home side a second goal.
The half-time whistle blew with Palace 1-0 up and looking comfortable.