Pompey once again took control of possession and had more shots than their relegation-threatened opponents.
But Danny Cowley bemoaned their play in both boxes following a 3-1 defeat to Swindon at the County Ground.
Some sloppy defending allowed Brett Pitman to bag a brace against his former club, with the second arriving from the penalty spot.
Ronan Curtis reduced the deficit, while George Byers and Andy Cannon both went close to finding an equaliser before Tyler Smith wrapped things up for the hosts.
And Cowley knows that the outcome is a blow to Pompey’s chances of securing a spot in the play-offs.
The Blues boss said: “It makes it very hard for us to get into the top six, but it’s not impossible and we’ll go right to the bitter end.
“We’ll be relentless in our work and our focus. We’ll be determined and resilient, but it’s fair that we get criticism for this game because we weren’t good enough at both ends of the pitch.
“We’re obviously disappointed – that’s an understatement. We haven’t done well enough in the past four games and have to accept that.
“For the amount of control we had in terms of both possession and territory, our chance creation wasn’t good enough.
"We’re obviously disappointed – that’s an understatement. We haven’t done well enough in the past four games and have to accept that."
“The thing I’m bitterly frustrated about is the fact we conceded so many goals and had total control – they had 11 touches in our box and scored three times.
“Ultimately, if you don’t do well enough at both ends of the pitch then you’re not going to win football matches.
“There were some good performances within our team and others who would want to be doing much better.
“But we’re trying to create a spirit and togetherness in our group and it doesn’t need me to come out and criticise individuals.
“The group has a good work ethic and attitude, although collectively we didn’t do well enough in the decisive areas.
“We left ourselves a mountain to climb – and it looked like we might climb it. There were two great chances after Ronan scored.
“But we were throwing caution to the wind and got done with a sucker punch. It’s a tough one to take.
“We’ll go away, analyse and learn and work out the solutions. There are four games to go and if we can find 10 or 12 points then it’s still possible.”