Cardiff City boss Malky Mackay praised the performances of teenagers Ben Nugent and Joe Ralls after they were called into action to cover a defensive crisis on Saturday.
The Welsh club were forced to overcome injuries to frontline defenders Ben Turner and Andrew Taylor, who both had to be substituted inside the opening half-hour.
Nugent and Ralls helped Cardiff City to a ninth straight home victory as Matt Connolly's headed goal in the 19th-minute gave the Bluebirds a 1-0 victory over their promotion rivals.
I'm delighted with the character of the team and the fact we kept another clean sheet at home. But that is no surprise to me because I see that from the players every day. Middlesbrough had been on a roll and we knew it would be a tough game. But it became tougher when we lost two players after 20 minutes. We had to put young players in and they did brilliantly well. To show that resilience against a good team showed the commitment to the cause and there are no egos at this club."