It was a game that rarely gave anyone inside Plough Lane the chance to draw breath.
Pompey trailed 2-0 in their Papa John’s Trophy opener at AFC Wimbledon, only for Ellis Harrison to score either side of the break.
The striker then completed his hat-trick, but the Dons hit back to secure a 5-3 victory in the Southern Group B contest.
And after making 11 changes, Danny Cowley was frustrated by the defensive frailties shown by his side.
The Blues boss said: “It was a crazy game of football and we’re really disappointed to lose after fighting so hard to be in such a good position after 80 minutes.
“To concede five goals is incredibly annoying – I can’t remember the last time one of my sides did that.
“There’s a lot to ponder and it’s a difficult one to analyse right after the game. We’ll have to watch it back and pick the bones out of it.
"To concede five goals is incredibly annoying – I can’t remember the last time one of my sides did that."
“We changed the system after about 15 minutes and went to a back three and looked much better after that.
“I’m pleased for Ellis and he was certainly one of the positives on the night – he looked a real handful for us.
“Mahlon Romeo was very assured on his debut and played with real athleticism on the right-hand side, while Louis Thompson was really strong in the second half
“It wasn’t easy because we lost Alex Bass and had to get an emergency loan keeper in, but Jake Eastwood did just fine.
“That was the first time he’d met the group and he didn’t really know our game idea, so that made it tougher.
“We picked the players who needed minutes and could have had a more experienced bench, but didn’t want this match to affect our preparations for Saturday.
“Some of the guys looked really short of match practice and will have to do better if they want a place in our team.”