Portsmouth boss John Mousinho felt the Sky Bet League One leaders “threw away” two points at Oxford.
Pompey came from behind at half-time to lead 2-1 – only for the U’s to snatch a point with a last-minute equaliser in a 2-2 draw.
James Henry’s 90th minute header after goalkeeper Will Norris could only parry a Mark Harris shot salvaged a point for Oxford and took them back into the play-off places.
Tyler Goodrham had fired Oxford in front before Pompey turned it around through Colby Bishop’s 15th goal of the season and a debut goal from Callum Lang.
Mousinho said: “You could break the game down into three parts.
“In the first half we were very poor. In the second half we were good and deservedly got in front and then there was six minutes of madness at the end.
“I felt the pressure was building and building and building from us, and we got the second goal which was fully deserved, then we threw it away at the end.
“My big message to the players at half-time was that we were not showing enough bravery on the ball and we were going backwards too often, playing into Oxford’s hands.
“We deserved to be up…we let ourselves down in not having enough attacking players in the right positions and we weren’t positive enough in the first half.
“But we turned that around. It’s just that, at 2-2 with five minutes to go we’ve not locked the game up enough and that gives us a flat feeling.
“The two goals we conceded – I thought we were awful.
“It’s obviously nice to see Callum score, that was why we brought him into the football club to make an impact, and he’s done that straight away.”
Oxford head coach Des Buckingham said: “The pleasing thing for me is that, regardless of the changes we had to make because of injuries – to Fin Stevens and Jamie Cumming – is how this group stays together and how hard they work.
“Portsmouth are a good team, you’re not top for no reason, and we knew they would come hard at us for goals in the second half.
“But the pleasing thing for me is that at 2-1 down heads don’t drop and we deservedly got a second goal.
“I’m extremely happy with the reaction we showed at 2-1 down.
“The two goals we conceded were two scrappy goals, but it’s always hard as a goalkeeper coming on at half-time. I don’t think Simon Eastwood was at fault for either goal, we just need to defend better.”
Buckingham was booked late on for protesting at referee Darren Drysdale’s decision in not awarding a penalty when Goodrham appeared to be brought down.
“That’s the first yellow card of my professional career,” he said. “I was very unhappy with some of the decisions. But I can’t have a go at players for a lack of discipline if I don’t show discipline myself.
“When I came in as manager my assistant Craig Short said to me how James Henry always pops up with important goals at important times.
“He’s a model pro and I was delighted to see the goal he popped in tonight.
“Overall, it’s a good point and one we can take into our Derby against Reading on Saturday.”
