Second-half goals from Gaston Ramirez and David Nugent enabled Boro to claim their first win in six games after Matthew Connolly's own goal had cancelled out a first-half opener from Cardiff full-back Fabio.
The game was the first match at the Riverside since the death of popular broadcaster Alastair Brownlee, and Boro fans marked the occasion with the unfurling of a giant banner bearing his face. It was a poignant gesture for a man who universally came to be known as 'the voice of the Boro'.
The Teessiders threatened throughout the first half, and only failed to forge ahead before the interval because of some unexpected profligacy from January signing Jordan Rhodes.
The striker spurned his first chance in the second minute, directing a weak downward header straight at David Marshall after Emilio Nsue crossed from the right, and wasted another opportunity seven minutes later as he blazed over from inside the penalty area after Albert Adomah played the ball into his path.
His final two chances came at the end of the first half, and saw him prod a wasteful half-volley over the bar from eight yards before heading Adomah's cross straight at Marshall from an unmarked position in the six-yard box.
In between those flurries, both sides scored, with Cardiff's goal proving sublime and Middlesbrough's equaliser much more ridiculous.
The visitors had barely featured when Tomas Kalas cleared a corner to Fabio 30 yards out, but the former Manchester United full-back rifled home an unstoppable long-range strike to claim his first goal since joining Cardiff.
Boro levelled five minutes later, although their goal owed much to some comical defending from Connolly. Ramirez headed the ball towards goal after Marshall parried Rhodes' shot, and from a position on the goalline, Connolly's attempted clearance cannoned into his own arm before rebounding into the net.
Cardiff travelled to Teesside on the back of a six-game unbeaten run, and Russell Slade's side, who carried a considerable threat throughout, would have reclaimed their lead three minutes into the second half had it not been for Boro goalkeeper Dimi Konstantopoulos, who got down superbly to keep out Lex Immers' goalbound header.
Marshall produced an excellent second-half stop of his own to keep out Stewart Downing's fierce drive, but was powerless to prevent Ramirez claiming his first goal since Boxing Day 2014 five minutes later. Rhodes cushioned a header into the Uruguayan's path, and he calmly stroked the ball home.
Boro should have claimed a third goal with nine minutes left, but after Ramirez was fouled by Joe Ralls in the box, Marshall kept out Grant Leadbitter's penalty.
However the hosts confirmed their superiority with seven minutes left as a flowing counter-attack ended in Nugent sweeping home a side-footed finish.