It was difficult to foresee a five-goal thriller at the interval.
A relatively dull first half at Blackpool yielded few clear-cut opportunities, with neither keeper being beaten as the sides trooped back down the tunnel.
But the second period was a completely different story, as Pompey twice forged ahead through Brett Pitman and Ben Close, only to be pegged back on each occasion.
It was the visitors who had the final say, though, as Pitman headed home a late winner to send the large travelling army home happy.
And Kenny Jackett was pleased with the way his side kept battling away to secure their desired outcome.
The Blues boss said: “It was end-to-end with a lot of chances and both sides were keen to attack.
“Fair play to our squad because they showed a lot of character to go ahead three times and then survive a siege at the end.
"When you have that many attacking guys on the pitch, you’ll have that kind of game."
“We probably don’t have enough defensively-minded players in the squad and when you have that many attacking guys on the pitch, you’ll have that kind of game.
“But we stayed strong and it caps a good week for us after the victory at Charlton in the Checkatrade Trophy.
“It’s good to win, but we had to earn it and the players certainly worked very hard. It’s never easy to come away and get a positive result.
“I was pleased for Ben to score his first goal for the club and he’s having a really impressive spell. He keeps improving and we’re delighted for him.”
There were a few surprises when the Pompey team was revealed ahead of kick-off, with Oliver Hawkins continuing at centre-back and Matt Clarke handed an unfamiliar role out wide.
Jackett said: “Left-back is a position we’ve struggled with because of injuries and we haven’t really been comfortable there.
“Matt’s best position is in the centre, but sometimes you want to be more solid in away games and that can result in wins.
“We wanted to be bigger at the back and – the own-goal aside – I thought that Hawkins was excellent.
“I also wanted to bring more experience into the team, with the likes of Gareth Evans, Danny Rose and Kyle Bennett providing that.”