Middlesbrough head coach Aitor Karanka has claimed that his side produced one of the worst performances of his reign in the 1-0 victory over Bolton Wanderers.

Alberto Adomah's first-half winner kept the pressure on Derby County, who hold a two-point advantage at the top of the Championship, but Karanka believes that Middlesbrough will need to improve if they are to compete with their promotion rivals.

"Four days ago, I was saying we had played one of our best games and lost. Today, we have played one of our worst games since I have been here, but we have won," the Spaniard told reporters.

"The important thing is that we have won three more points. We will have to analyse the game because I cannot really explain anything now. The good thing is the three points, but it's difficult for me to understand what happened because I didn't really recognise some of my players.

"We have fixed one part of our mistakes, and that is the defensive errors. But now we have to fix the attacking mistakes as well because it is not possible to finish the games with a win when we have problems like this."

Karanka's side returns to action against Sheffield Wednesday on Saturday afternoon.