All over. Big, big win for Hull. They're out of the relegation zone.
Follow reaction to this game here .
Marco Silva doesn't look too happy on the touchline. He should be. The fans are delighted.
Middlesbrough's winless run is going to stretch to 13 games.
Hull look more likely to score a fifth here.
Five minutes added time.
Spurs ahead at the Liberty. That is greeted by huge cheers in Hull.
Just minutes left.
Big news at the bottom. Spurs have equalised against Swansea. That means Hull are out of the bottom three as it stands. They're just running down the clock here.
Markus Henriksen is on for the impressive Kamil Grosicki.
Boro haven't quite given up yet. Cristhian Stuani almost gets in ahead of Eldin Jakupovic in the six-yard box but the goalkeeper manages to parry the ball away.
Adama Traore has taken a knock and is limping. Boro have used all three of their subs.
A goal one minute, an injury the next.
Harry Maguire has to go off after being clattered by his own goalkeeper a few minutes ago.
He's probably done enough to seal three crucial points for his side though.
Michael Dawson is the man to come on.
Cristhian Stuani is on for Rudy Gestede for Boro.
Middlesbrough fans it is not looking good. With Swansea winning against Spurs you're eight points from safety.
That result is tough on Hull too by the way. They'd be out of the drop zone if Tottenham were to get an equaliser at the Liberty Stadium.
"We've got Marco Silva, we've got Marco Silva," chant the home fans.
What a remarkable job he is doing.
Patrick Bamford replaces Alvaro Negredo for Boro.
Hull have played really good football and I think they deserve this.
This one goal comes from a set piece rather than tidy play though.
Andrew Robertson swings in a deep free-kick and Harry Maguire is totally unmarked at the back stick and heads inside the far post.
Hull are testing out the legs of the Boro defence playing a couple of long balls over the top for their forwards to chase.
Kamil Grosicki is showing off all of his tricks on the left wing for Hull. He has been impressive. Between him and Adama Traore we've seen enough tricks for a lengthy YouTube compilation tonight.
Middlesbrough look to have gone 3-5-2 after that recent substitution. They haven't quite come to grips with the formation in an attacking sense however. Steve Agnew is barking out instructions on the touchline.
Harry Maguire heads over from a corner for Hull.
Less than half an hour left. Middlesbrough need a goal desperately. In fact, realistically they need two with Swansea winning at home to Tottenham.
Hull look the side more likely at the moment though.
First change for Middlesbrough. Adlène Guédioura is on for James Husband.
Hull have their first meaningful effort of this half and force Victor Valdes into a good low save.
Alfred N'Diaye has the shot from the right side of the area and Valdes gets down well. You wouldn't expect a multiple Champions League winner to be beaten with a strike like that however.
This must be a difficult one for Middlesbrough fans to fathom. Their side has scored two goals in a game for the first time since December but have been far more open than throughout the rest of the season.
What can they do? Middlesbrough sit tight in matches and slip towards the relegation zone and now show more attacking intent but concede three in the first half against their relegation rivals.
Abel Hernandez is in trouble here. The Uruguayan - the scorer of Hull's third goal - looks to have a muscle problem.
He's off and is replaced by Evandro, who himself is returning from injury.
The first test of the Hull defence in this second half comes via a free-kick clipped into the box by Stewart Downing. A free-kick is given to the home side though, cue ironic cheers from the Hull faithful.
The second half has just begun. If it is anything like the first we're in for a treat.
That goal really does change things.
Hull were much the better team in that half, pushing much higher up the field, but that controversial goal just before the break gives the game a different complexion.
Tanay Apte: What's with Middlesbrough's left backs? First Friend, now Husband. One big (un)happy family?
Excellent spot. If you can come up with any other Hull or Middlesbrough related puns let me know at #bbcfootball or text 81111.
That's half-time. Marco Silva is not happy. He is certain that De Roon's goal should have been disallowed.
The officials have got this one wrong. A Middlesbrough corner comes in from the right and Ben Gibson heads the ball towards goal where Marten de Roon heads home inside the six-yard box.
The Dutchman was clearly in an offside position however and, despite a discussion between referee Michael Oliver and his assistant, the goal is given.
The game has now gone into a little lull just before half-time. It is no wonder as it has been intense stuff. There's a minute to go until the break.
Boro have got Alvaro Negredo that's what. He's already got one goal and is inches away from getting another.
The Spain international curls a long-range strike just wide of the left-hand post with Jakupovic beaten.
What have Middlesbrough got?
They'll be seven points behind Hull if this stays like this and eight points from safety. Surely they need to turn this one around? Grosicki wins another corner for Hull but it comes to nothing. What a job Marco Silva is doing on Humberside.
Middlesbrough almost get one back straight away. What a game!
Stewart Downing's shipped cross is met by Rudy Gestede's powerful header is saved by Eldin Jakupovic with a little help from the crossbar.
The Swiss 'keeper gives a big fist pump afterwards. That was an important save.
This is really good football from Hull.
A well worked move ends with Kamil Grosicki's square ball being converted by Abel Hernandez. Hull have breathing space.
For the first time in the game Middlesbrough have a lengthy spell of pressure.
Adama Traore dances down the right and chips a ball into the box but Alvaro Negredo's swinging volley is straight at Jakupovic.
After going behind after just five minutes in such a crucial game, Hull could have crumbled but they have been excellent.
They're fully deserving of this lead. For the second game in a row they've turned the game on its head.
Hull have been by far the better team and are now ahead.
Alfred N'Diaye lobs the ball over his head towards the danger area where Ben Gibson misses his clearance. Abel Hernandez then nods the ball to Oumar Niasse who cooly finishes.
Middlesbrough look to come forward down their left through James Husband and Stewart Downing but it comes to nothing.
Those two are at very different stages of their top-flight careers, Downing making his 400th appearance and Husband his Premier League debut.
Hull are just dominating possession. Marten de Roon puts in a nasty tackle on Alfred N'Diaye and Marco Silva and Steve Agnew have words afterwards on the touchline.
Adam Clayton now receives a booking for a cynical foul on the edge of the area.
Abel Hernandez takes the resulting free-kick from a dangerous position inside the 'D' but he shoots wide of Victor Valdes' right-hand post.
Sam Clucas is the first man in the book for a crunching tackle on Marten de Roon.
Chants of "you're going down with the Mackems" ring down from the stands. I'm not sure which fans are singing it but, to be honest, it could be true for both teams if the result stays like this.
Aside from their early goal, Middlesbrough have struggled to get hold of the ball. They've had just 24% of the possession in fact.
Whenever they can they're looking for Adama Traore on the right. The youngster was seen in a lengthy discussion with his manager Steve Agnew before kick-off. He'll be key if Boro are to get the win they desperately need tonight.