Peterborough midfielder Grant McCann's late penalty denied Hull the chance to return to the Championship's top two.
He struck with 11 minutes remaining just as Steve Bruce's side appeared on course to back into the automatic promotion places.
Leicester's 1-0 win over Middlesbrough on Friday had dropped Hull to third.
Joe Newell's first-half own goal had given the Tigers the lead only for McCann to score from the spot after James Chester fouled Tommy Rowe.
The result spared Peterborough a 10th home league defeat and was the club's first draw at London Road since 21 April 2012.
Dwight Gayle was unable to add to the 10 goals he has scored for Peterborough since his arrival on loan from Dagenham & Redbridge at the end of November when he headed wide after eight minutes. Jaanai Gordon-Hutton and Robbie Brady went close for the hosts soon after.
Hull threatened with Liam Rosenior, Nick Proschwitz and Paul McShane all heading at goal before the half-hour mark but Posh did not heed the warnings.
The visitors snatched the lead on the half-hour, Newell inadvertently diverting the ball beyond his own goalkeeper Robert Olejnik after a whipped cross by Robert Koren.
But the hosts equalised from the penalty spot after Rowe was brought down by Chester.
Gayle wanted to take the spot-kick, but McCann took the ball off him and stroked his shot past Hull goalkeeper David Stockdale.
Peterborough survived a late scare when McShane's diving header had to be parried away by Olejnik.
Peterborough manager Darren Ferguson: "A point was the least we deserved and I wouldn't have been surprised if we had gone on to win after getting ourselves level.
"Home form is crucial when you are fighting to stay up and I know for a fact that the relegation battle is going to go right down to the wire."
Hull City boss Steve Bruce: "You're always disappointed to be pegged back in the final few minutes of a match, but in all truth I don't think we deserved anything more than a point.
"We gave away a soft penalty which I have absolutely no complaints about, but I can't be too disappointed to be sat third in the league with only goal difference keeping us out of the automatic promotion places."
Live Text Commentary
Full Time The final whistle goes and the game is over.90:00 +4:04
Shot from just outside the penalty area by Nick Proschwitz misses to the left of the target.90:00 +1:58
Nick Proschwitz takes a shot. Save by Robert Olejnik.90:00 +1:22
The ball is delivered by Cameron Stewart, Scott Wootton makes a clearance.89:47
Nick Proschwitz is flagged offside by the assistant referee. Michael Bostwick takes the free kick.88:42
Mark Little challenges Robbie Brady unfairly and gives away a free kick. Free kick crossed left-footed by Robbie Brady from left channel, clearance by Joe Newell.87:22
Unfair challenge on Liam Rosenior by Joe Newell results in a free kick. David Stockdale restarts play with the free kick.85:46
Direct free kick taken by Scott Wootton.85:46 Booking
Booking Corry Evans booked for unsporting behaviour.85:44
Free kick awarded for a foul by Corry Evans on Grant McCann.83:07
The free kick is swung in right-footed by David Meyler, clearance by Joe Newell. The ball is crossed by David Meyler, Cameron Stewart takes a shot. Scott Wootton gets a block in. Corner taken by Tom Cairney from the left by-line, Paul McShane takes a shot. Save made by Robert Olejnik.83:07 Substitution
Substitution Stephen Quinn goes off and Tom Cairney comes on.83:07 Substitution
Substitution Cameron Stewart is brought on as a substitute for Robert Koren.83:07
Tommy Rowe concedes a free kick for a foul on David Meyler.81:40 Substitution
Substitution Danny Swanson comes on in place of Jaanai Gordon-Hutton.80:57
Michael Bostwick gives away a free kick for an unfair challenge on Nick Proschwitz. Paul McShane takes the direct free kick.78:32
Assist on the goal came from Tommy Rowe.78:31 Goal scored
Goal! - Grant McCann - Peterboro 1 - 1 Hull City Placed penalty scored by Grant McCann. Peterborough 1-1 Hull.77:29
Foul by James Chester on Tommy Rowe, Penalty awarded.76:41
Grant McCann fouled by David Meyler, the ref awards a free kick. Direct free kick taken by Joe Newell.
A cross is delivered by Liam Rosenior, save made by Robert Olejnik.74:37
Effort from the edge of the penalty area by Jaanai Gordon-Hutton goes wide of the left-hand post.73:14
Nathaniel Mendez-Laing produces a cross, David Meyler makes a clearance.72:44
Free kick awarded for an unfair challenge on Mark Little by Stephen Quinn. Direct free kick taken by Mark Little.72:30
Corry Evans gives away a free kick for an unfair challenge on Dwight Gayle. Free kick taken by George Boyd.70:39
Shot from outside the box by Grant McCann misses to the left of the goal. Outswinging corner taken left-footed by Grant McCann, Alex Bruce makes a clearance.69:17
A cross is delivered by Mark Little, save by David Stockdale.68:16
Michael Bostwick crosses the ball.66:42
Grant McCann has a direct shot on goal from the free kick.66:42 Booking
Booking The referee books Paul McShane for unsporting behaviour.66:23
Mark Little fouled by Paul McShane, the ref awards a free kick.65:44 Substitution
Substitution Nathaniel Mendez-Laing on for Shaun Brisley.65:29
The ball is sent over by Jaanai Gordon-Hutton.64:01
The official flags Jaanai Gordon-Hutton offside. James Chester takes the free kick.60:34 Substitution
Substitution Grant McCann is brought on as a substitute for Davide Petrucci.60:34
Inswinging corner taken by Robbie Brady.60:34 Substitution
Substitution Corry Evans replaces Jay Simpson.60:34
Robbie Brady takes a shot. Blocked by Shaun Brisley.59:50
The offside flag is raised against Jaanai Gordon-Hutton. David Stockdale restarts play with the free kick.59:28
The referee blows for offside. Robert Olejnik takes the indirect free kick.57:01
Stephen Quinn produces a left-footed shot from just outside the penalty box that misses to the left of the target.56:21
Stephen Quinn delivers the ball, Mark Little gets a block in. Corner taken by Robert Koren, Tommy Rowe manages to make a clearance.53:52
The ball is swung over by Shaun Brisley, Stephen Quinn manages to make a clearance.51:58
David Meyler concedes a free kick for a foul on Dwight Gayle. Davide Petrucci takes the direct free kick.51:23
A cross is delivered by Stephen Quinn, clearance by Shaun Brisley.50:00
Unfair challenge on Mark Little by Robbie Brady results in a free kick. Davide Petrucci takes the direct free kick.49:25
Jaanai Gordon-Hutton produces a cross, clearance by Alex Bruce.48:30
The ball is delivered by Robert Koren, save by Robert Olejnik.47:41
Shot by Davide Petrucci from outside the box goes high over the target.46:37
Tommy Rowe is caught offside. David Stockdale takes the free kick.45:01
The referee starts the second half.45:00 +1:13 Half time
Half Time The ref blows to signal half-time.43:52
Paul McShane fouled by Jaanai Gordon-Hutton, the ref awards a free kick. David Stockdale takes the direct free kick.41:30
Mark Little crosses the ball, save made by David Stockdale.39:09
Jaanai Gordon-Hutton has an effort at goal from just outside the area which goes wide of the left-hand post.38:54
Foul by Alex Bruce on Shaun Brisley, free kick awarded. Joe Newell restarts play with the free kick.38:17
The official flags Nick Proschwitz offside. Robert Olejnik takes the free kick.38:02
Robbie Brady gives away a free kick for an unfair challenge on George Boyd. George Boyd takes the free kick.32:59
Assist on the goal came from Robert Koren.32:59 Goal scored
Goal! - Joe Newell - Peterboro 0 - 1 Hull City Joe Newell puts the ball into his own goal. Peterborough 0-1 Hull.31:25
Robert Koren takes a shot. Shaun Brisley gets a block in. Robert Koren takes a inswinging corner.29:13
Robbie Brady delivers the ball, blocked by Mark Little. Corner taken right-footed by Robert Koren, Paul McShane takes a shot. Save by Robert Olejnik.28:06
Robbie Brady delivers the ball, Header by Nick Proschwitz from deep inside the penalty area misses to the right of the target.26:52
Robbie Brady crosses the ball, Headed effort from deep inside the area by Liam Rosenior misses to the right of the target.26:25
The referee blows for offside against Dwight Gayle. Indirect free kick taken by James Chester.24:17
Robbie Brady has an effort at goal from outside the area missing to the wide right of the target.23:27
Robert Koren takes a shot. Scott Wootton gets a block in. Inswinging corner taken right-footed by Robert Koren played to the near post, Tommy Rowe makes a clearance.23:00
Free kick awarded for a foul by Mark Little on Robbie Brady. Direct free kick taken by Stephen Quinn.21:32
Robert Koren takes a shot. Save by Robert Olejnik.19:34
The ball is crossed by Robbie Brady, Michael Bostwick manages to make a clearance.15:52
Robbie Brady concedes a free kick for a foul on Mark Little. Robert Olejnik takes the free kick.15:44
The ball is sent over by Stephen Quinn.14:35
Jaanai Gordon-Hutton produces a right-footed shot from just outside the box that goes wide right of the target.13:16
Free kick awarded for a foul by Jay Simpson on Shaun Brisley. Free kick taken by George Boyd.13:05
Tommy Rowe produces a cross, clearance by Paul McShane.12:11
Foul by Jaanai Gordon-Hutton on James Chester, free kick awarded. David Stockdale takes the free kick.11:02
James Chester challenges Dwight Gayle unfairly and gives away a free kick. Free kick taken by George Boyd.10:07
The ball is delivered by Tommy Rowe, Paul McShane manages to make a clearance.9:42
The ball is crossed by Dwight Gayle, Liam Rosenior gets a block in.7:58
Davide Petrucci sends in a cross, Headed effort from inside the area by Dwight Gayle misses to the left of the target.6:21
Centre by Robbie Brady, Michael Bostwick makes a clearance.5:57
James Chester takes a shot. Shaun Brisley gets a block in.3:05
Jaanai Gordon-Hutton challenges James Chester unfairly and gives away a free kick. James Chester takes the free kick.1:52
Dwight Gayle concedes a free kick for a foul on Stephen Quinn. Stephen Quinn takes the free kick.0:00
The match has kicked off.
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