Jonson Clarke-Harris headed in a late equaliser for Peterborough as the Sky Bet Championship's bottom club held promotion-chasing Luton to a 1-1 draw at London Road.
Although a point does not do much for Posh's survival hopes, as they remain well adrift of fourth-from-bottom Reading, the result was the least they deserved for a spirited display.
It was a frustrating night for the Hatters, who led for most of the second half through Danny Hylton's goal but were ultimately held for the second successive game to remain fourth in the table.
Peterborough were lively at the start and came close to going ahead in the sixth minute when captain Frankie Kent's header from Joe Ward's corner was tipped onto the post by James Shea.
The Luton goalkeeper was quickly called into action again when he had to push out Harrison Burrows' effort from 25 yards.
The visitors settled and were almost ahead from their first real chance, after 18 minutes, when Posh goalkeeper David Cornell did well to tip over Elijah Adebayo's header from Fred Onyedinma's cross.
Jack Taylor then became the latest home player to test Shea when he shovelled his shot from 25 yards behind at his near post.
The Hatters were forced into a change just after the half-hour when the injured Cameron Jerome was replaced by the fellow experienced head of Henri Lansbury.
Peterborough continued to pose a threat, with Kwame Poku volleying wide after Josh Knight's cross was headed towards out his way.
The Hatters needed to improve after the break and Lansbury forced Cornell into a save from just outside the box shortly after the restart.
Two minutes later, a great pass from Lansbury put Onyedinma in behind down the right and his low ball across the six-yard box was gleefully turned in by Hylton for the opener.
Peterborough struggled to make openings in response, with Poku's wild shot off target from long range symbolic of their growing frustration.
They really should have drawn level in the 78th minute when a dangerous ball by Ward evaded Clarke-Harris, before substitute Ricky-Jade Jones bundled wide from close range.
But the home side eventually equalised with three minutes remaining when another good cross by Ward was met by Clarke-Harris, whose header found its way into the bottom corner.
The hosts were not satisfied with a point and came close when Burrows' cross from the left found Taylor, who could not keep his header down.
Then, in the final minute of five added on, Clarke-Harris came within a whisker of winning the contest when his low drive from 25 yards came back off the post.
What the managers said...
Luton's Nathan Jones: "We were 1-0 up on 85 minutes, so we've just got to see the game out, really, and we didn't do that.
"We had a warning just before, with a delivery, and they've had a chance back stick and they've scored, and to be fair they could have won it.
"We probably should have lost the game, we haven't been anywhere near our best tonight, but credit Peterborough: they're grafting, they needed a win, they went for it, they were really positive. They had a bad result at the weekend [against Middlesbrough], so they've come out fighting. Give them credit, but we weren't at the levels we were.
"We showed one bit of quality tonight - the one time we won a first contact, first time we got it down, first time we showed any kind of quality, we scored. I'm a bit frustrated; one, we didn't see the game out and, two, the level of performance."
Peterborough's Grant McCann: "I thought, for 85 minutes of the game, we were the better team.
"There was a five-minute spell in the second half when they got on top of us and scored in that spell, and that's the Championship for you. Teams score in their spells and that's what happened in that five-minute spell, but I thought we rallied, we got better.
"We kept working, we had to deal with [Elijah] Adebayo, and the long ball into him, and that's the way they play and we did that for most of the game.
"The last 20 minutes I thought we were excellent and there was only going to be one team that was going to win it. If I look over the last six games, I think we've been really competitive in five of them. I see the team tonight fighting."