Billy Sharp scored and missed a penalty on his 300th appearance for Sheffield United as struggling Hull were easily beaten at the MKM Stadium.
Sharp finished off a sweet move by heading in Morgan Gibbs-White's perfect right-wing cross to put the Blades in front.
Although Hull goalkeeper Matt Ingram superbly saved Sharp's spot-kick just before half-time, the visitors took control after the break.
Two John Egan headers - both from corners - killed off any hope of a Hull comeback despite Keane Lewis-Potter's consolation, their first goal in more than 10 hours.
The win extends Slavisa Jokanovic's side's unbeaten run to five games, while the Tigers slipped into the relegation zone.