Middlesbrough manager Aitor Karanka has claimed that his side paid the price for one mistake during their 1-0 defeat to Chelsea this afternoon.

Boro held their own for long spells at the Riverside Stadium, but failed to deal with a corner late in the first half, which allowed Diego Costa to fire home the only goal of the game.

Karanka was left disappointed with the result, but believes that his side's performance once again proves that they belong in the division following on from recent draws away to Arsenal and Manchester City.

"Playing against teams like Chelsea, we knew that it was going to be a really, really tough game, but once again we showed everybody that we can compete against the best teams in the league and once again, one mistake punished us," he told reporters.

"To concede a goal from a set piece is a mistake. I don't want to blame any player because I say always we win as a team and we lose as a team, but when you concede a goal from a set piece for me, it is a mistake.

"You can't be pleased when you have lost a game, especially at home, but I am really pleased with the attitude of the players because because playing in the way that we have been doing in the last month and a half, we are in the right way."

The defeat leaves Boro 15th in the Premier League table, just one point clear of the relegation zone.