The defining moment of the game came minutes before half time when the Argentine coolly finished from the spot after Marvin Emnes was brought down under a clumsy challenge from Gabor Gyepes.
The win elevates Boro out of the relegation zone for the first time since Mowbray took over and they were worthy winners in what was a close game with Dave Jones' side.
Boro had started the day second from bottom, while their opponents were second top, looking to take capitalise on QPR's slip up against Watford the night before.
The first half saw both sides fail to create any clear cut chances but Boro looked the more likely to break the deadlock and six minute before the interval, Mowbray's side took the lead.
After scoring against the Bluebirds while on loan at rivals Swansea earlier in the season, Emnes again proved a thorn in Cardiff's side and after being brought down in the box by Gyepes, referee Anthony Bates pointed to the spot.
Up stepped Arca, who confidently slotted the ball low into the right hand corner to put Mowbray's side 1-0 just before the break.
After the interval, Jones introduced Michael Chopra to the game in a bid to give the Craig Bellamy some much needed support.
That did spark a 15 minute spell in which the away side pressed for an equaliser with Bellamy smashing the bar with a thunderous strike and Kevin McNaughton forcing a full-stretch save from Jason Steele.
Despite Cardiff's attempts to grab a late equaliser, Boro held off their advances to claim a valuable three points, which lifts them out of the bottom three.
Source: Northern Echo
Source: Northern Echo