When Colby Bishop tucked away his second penalty of the afternoon, it looked as if Pompey were cruising into the third round of the Emirates FA Cup.
They had shaken off falling behind to MK Dons against the run of play to roar into a 3-1 lead, with Reeco Hackett levelling before the first spot-kick was converted.
But Mo Eisa struck to reduce the visitors’ deficit and leave most inside Fratton Park feeling relieved at the sound of the final whistle.
Danny Cowley admitted that Pompey finished the tie on the back foot, although was happy with a week that saw progress in two different competitions.
The Blues boss said: “We’re really pleased to have navigated our way through two really tough cup ties in the past few days.
“There were only 15 fit senior players available and we had four of our scholars on the bench, who had all played for the academy in the morning.
“We were facing a possession based side with no Dane Scarlett or Owen Dale, who are arguably our most aggressive pressers, so it was probably the worst draw available for us.
"The supporters were great because they could see the energy was low and stayed right with us to get the boys over the line."
But I thought we did really well up until after we scored the third goal – with Jay Mingi excellent in the first half – and then it wasn’t quite right.
“We started to play for the end of the game and were disappointed with that last half-hour because we lost momentum.
“When that happens, though, you need to dig deep and show a lot of fortitude and character – that’s exactly what we did.
“The supporters were great because they could see the energy was low and stayed right with us to get the boys over the line.”
Pompey will discover who they are facing early in the new year when the draw takes place on Monday evening.
Cowley said: “I always remember the big games this club have had in the past and the intensity of the atmosphere at Fratton Park.
“That would transcend through my television set, so to get a Premier League club at home would be special.”