Boro's problem is they appear incapable of stringing a run of results together and their lack of consistency could see them miss out on a play-off place that was a minimum target at the start of the season.
Boro made two changes from the side which beat QPR thanks to two Barry Robson penalties. Andrew Taylor came in for Emanuel Pogatetz who was nursing a knee injury, and Julio Arca replaced Chris Killen who dropped to the bench.
Killen was playing for New Zealand against Mexico in Los Angeles in midweek with Jeremie Aliadiere pushed up alongside Leroy Lita in attack.
The pre-match entertainment for the away fans was a march by Cardiff supporters to show their displeasure with the way their club is being run, directing their ire at Bluebirds chairman Peter Ridsdale.
It didn't appear to affect the Cardiff players. A goal from Jay Bothroyd inside three minutes was enough to see off the Teessiders, and despite a spirited second half display Boro couldn't find a way back.
They thought they had just after the hour mark but David Wheater's header was harshly ruled out for a Leroy Lita handball and despite Bluebirds goalkeeper David Marshall pulling a string of saves they couldn't find an equaliser.
Cardiff City: Marshall; Matthews, Gerrard, Gyepes, McNaughton; Burke, Blake, Rae, McCormack; Chopra, Bothroyd. Subs: Enckelman (gk); Quinn, Capaldi, Taiwo, Wildig, Feeney, Meades.
Middlesbrough: Coyne; Naughton, Wheater, McManus, Taylor; O'Neil, Robson, Arca, Flood; Aliadiere, Lita. Subs: Jones (gk); Miller, Grounds, Williams, Bennett, Franks, Killen.
Source: Northern Echo
Source: Northern Echo