Boro went ahead on 28 minutes with their first effort of note, as Marcus Tavernier found the net from 25 yards with a powerful right-footed effort.

Riley McGree's deflected shot on 53 minutes sealed a vital victory.

Middlesbrough knew a win was imperative in their bid to finish in sixth place, with no room for slip-ups against a Cardiff side safe from relegation and with little to play for.

Wilder made one change from the Boro side that drew 1-1 at Swansea City on Saturday, with on-loan Arsenal striker Folarin Balogun replacing Josh Coburn in attack.

Bluebirds boss Steve Morison - who has admitted he is already eyeing next season - made two changes from Cardiff's 1-0 defeat at Sheffield United, with Wales midfielders Rubin Colwill and Will Vaulks replacing the injured Joel Bagan and Joe Ralls.

The visitors also switched formation as they lined up with an unfamiliar back four and a midfield diamond, and they looked comfortable as they restricted the hosts.

Middlesbrough began to exert more pressure and they found a breakthrough when Jonny Howson picked out Tavernier, who fired home from 25 yards as Cardiff's defenders failed to close him down - despite goalkeeper Dillon Phillips getting a hand to the ball.

Middlesbrough had lost three successive league games at the Riverside Stadium before beating Cardiff

Cardiff chances were few in the first period, but they did create a good opening in stoppage time when Colwill's impressive run and pass found Jordan Hugill in the penalty area but he fired over the crossbar.

The Bluebirds have scored more than 80% of their league goals this season in the second half of games.

But by the time Max Watters forced Boro goalkeeper Luke Daniels to tip his effort over the crossbar, the hosts were 2-0 ahead as McGree's shot deflected off Curtis Nelson and past Phillips' despairing dive.

Watters almost atoned for his miss when his cross struck the Boro bar with Daniels beaten, but it was the hosts who then almost added to the scoring when McGree headed wide from Marc Bola's cross.

Middlesbrough won the reverse fixture 2-0 in October - in a contest that proved the final straw for Bluebirds boss Mick McCarthy, who stepped down following an eighth straight defeat - and they completed a first league double over Cardiff since the 2014-15 season with relatively few scares.

Cardiff's 23rd league defeat of the season - having lost four in a row and five in six - leaves them in 19th place.

Middlesbrough boss Chris Wilder:

"It's job done. We understood the job we needed to get done and we did that.

"The first goal was a big one, it settled us down and was a big moment we needed.

"I don't think it was a real flowing performance, but it was a 2-0 win.

"We take it to the 45th game of the season and I think that's all we can ask of the boys."

Cardiff boss Steve Morison:

"We just weren't good enough in the final third, we just didn't have enough, it's frustrating.

"When we have our moments we don't take them. It seems like the same old story.

"It hurts. I get out of bed every day to win games of football and hate it when things like this happen.

"The question I've asked the players in the dressing room is, does it hurt them enough to lose?"