Middlesbrough boss Aitor Karanka hailed a "massive" three points for his side after Gaston Ramirez headed the only goal of the game to sink Hull at the Riverside Stadium.
The Uruguayan's close-range finish capped a dominant performance by Boro, who were still forced to cling on for a point after Adama Diomande missed two golden chances in injury time.
The home side's first win in four games steered them clear of the relegation zone and Karanka said: "It's massive because they are a direct opponent and apart from the score we showed we are better than them.