Keiron Dyer's first league goal in six years and a debut strike by Shola Ameobi have given Middlesbrough a 2-0 half-time lead over Cardiff City.
The league leaders threatened as early as the first minute, with Craig Bellamy taking Fraizer Campbell's headed pass on the half-volley and firing wide.
Cardiff may have started out on the front foot, but they fell behind in the 13th minute when Middlesbrough's January signing Dyer stabbed home Ishmael Miller's low cross from two yards out.
A debut goal for Ameobi put the hosts 2-0 to the good in the 17th minute, the Newcastle United loanee dancing through the Cardiff defence and curling one beyond David Marshall.
Cardiff's lead at the top of the division will be reduced to five points should today's scorelines remain the same.
