Andre Dozzell's 87th-minute equaliser saved a point for 10-man Portsmouth in their fraught 2-2 Sky Bet Championship relegation dogfight with Oxford.
Keshi Anderson gave Pompey a ninth-minute lead but Connor Ogilvie's straight red card seven minutes later gave them an uphill battle.
Brodie Spencer equalised before Tottenham loanee Will Lankshear's diving header gave him his 10th goal of the season and seemingly the three points.
But midfielder Dozzell steered home late on to give Portsmouth a place and point advantage over Oxford - with the two sides separated by just a point, with Leicester in between.
The frantic tone was set in a frenetic opening five minutes, where the ball bounced from end to end.
Yunus Konak speared over the bar for Oxford and then Ciaron Brown poked a Gustavo Caballero cross against his own post.
So, it was little surprise that the deadlock was broken in just the ninth minute. Ogilvie's deep cross was headed back across goal by Caballero, Colby Bishop nodded into the path of Anderson who fooled a defender with a dummy before lashing home.
The goal was Anderson's first since he netted for Birmingham against Pompey in November.
The midfield frenzy had not translated into heavy fouls, so when referee Joshua Smith dismissed Ogilvie for a tackle on Stan Mills, it surprised all inside Fratton Park.
The Portsmouth left-back had attempted to win the ball, but his trailing leg trapped Mills' in a scissoring motion. It was only Portsmouth's second dismissal of the campaign.
In the aftermath of the sending-off, a bottle was thrown towards the officials from the home support.
Pompey boss John Mousinho immediately responded by substituting Conor Chaplin for defender Jordan Williams but the replacement quickly caused attacking problems of his own as he pulled the ball back for Caballero - who skied his effort.
Despite having a man advantage for half an hour in the first half, Oxford failed to register a shot on target before the break.
The double change at the break by visiting boss Matt Bloomfield brought a change and a new attacking impetus, which immediately resulted in a leveller.
Mills was able to cut in from the left to force Nicolas Schmid into a stretched save but he could only push the ball into the path of Spencer to bundle in for his first Oxford goal.
Both sides spent the majority of the second half mustering half-chances before an action-packed last 10 minutes.
Michal Helik's cultured inswinging cross in the 81st minute was met by a diving header from Lankshear in the 81st minute which appeared to be moving Oxford above their opponents.
However, that changed when Dozzell found the bottom corner after a pullback from Millenic Alli with three minutes to go.
Jamie Mackie on Your Site Football:
"I don't think it's a red card. I'm not convinced the ref would have given it. I think the linesman on that side is quite close, and I think that quite early on they've communicated.
"Look, it wasn't a great touch, and he's obviously scrambling a little bit, and standing Mills is quick onto it. I just look at it there. Okay. Look, he's wrapped his leg round him. But I look and go that the studs aren't really in play. I think it's not massively high.
"It's not like if he wrapped his legs around him, and it's sort of like quad height. It is quite low."
Portsmouth's John Mousinho:
"It is still extremely tight at the bottom of the table. It was a must-win for both teams so I'm not sure it has helped either side. In the circumstances, we will take the point.
"I thought the character and the way the boys went about it was excellent. To be able to do that in a game of magnitude was pleasing, especially to come back into the game after the hammer blow of Oxford's second goal.
"My take on the red in real time was that I don't think anyone was expecting it to be a red - including Oxford.
"I don't think it is a red card and if you are going to do something as monumental as that you have to be 100 per cent sure, and I don't think it is clear cut.
"I'm not going to hide away from Ogilvie not needing to make the challenge but if that is a red card then there is going to be a fair few red cards dished out over the next year."
Oxford's Matt Bloomfield:
"We could have won. We got our noses in front so close to the end of the game.
"We worked so hard to get ahead and feel terribly disappointed we're not walking away with three points.
"Nothing was decided today. The lads are disappointed, as am I, that we haven't won the game, because we have got so close.
"At the same time, it is my job as a leader of the group to pick everyone up for the next game. We can't be too down. We have five matches left and we have to keep hunting."
