Dominant Hull moved another step closer to Sky Bet Championship safety as they deservedly beat Birmingham 1-0 at St Andrew’s.
Liam Rosenior’s Tigers were by far the better side but had to wait until the 77th minute for Oscar Estupinan’s 10th goal of the season to stretch their unbeaten away record to six games.
Blues, unchanged in four games and with a day less to prepare, looked tired and struggled throughout.
Hull, who had drawn their last three games, were quicker to the ball and created several chances.
Greg Docherty robbed Juninho Bacuna and his drilled effort hit Marc Roberts to slice behind.
Birmingham kept wasting possession and were almost punished when Regan Slater dragged a low drive just wide of John Ruddy’s right-hand post.
Birmingham could have won a penalty at the midpoint of the first half before Hull had further opportunities.
Blues forward Tahith Chong appeared to be pushed in the back by Hull left-back Jacob Greaves challenging for a header after captain Troy Deeney won a long kick from Ruddy in the air.
Referee Stephen Martin waved play on, and Deeney’s snapshot hit the legs of goalkeeper Matt Ingram. It was to be his only save.
Hull resumed their dominance and Ruddy was forced into an instinctive stop from Sean McLoughlin’s first-time curling shot from Jean Michael Seri’s free-kick, before Docherty’s 25-yard drive was deflected behind off Deeney.
Blues finally broke with some purpose at the end of the first half when Emmanuel Longelo sent an angled drive wide after a surging run from Hannibal Mejbri.
Hull continued where they had left off after the break.
Alfie Jones scooped high over the bar from four yards out after Estupinan’s header had been blocked from Greaves’ cross.
Birmingham head coach John Eustace made a double substitution in the 59th minute in a bid to shake his side into life.
Lukas Jutkiewicz and Jordan Graham replaced Dion Sanderson and Longelo as Blues switched from 3-5-2 to 4-3-1-2.
But it was Hull who continued to threaten, and the visitors had the ball in the net in the 68th minute only to be denied by the offside flag as Longman stooped to head home at the far post from Docherty’s cross.
But Hull did not have much longer to wait for one that did count. Colombia international Estupinan got ahead of Roberts to stab home Cyrus Christie’s cross after Tyler Smith found him on the overlap.
A rare Birmingham chance came five minutes from time when McLoughlin sliced Jordan James’ cross over his own bar.
Incredibly, Ruddy went close to an equaliser when he headed wide from Jonathan Leko’s cross with the last action of the game after coming up for a corner.