With a two-goal advantage and almost three-quarters of possession, Pompey appeared to have three points wrapped up by the break at Shrewsbury.
Marcus Harness and John Marquis had both found the target in an opening 45 minutes that the visitors dominated.
But Nathanael Ogbeta reduced the Shrews’ deficit straight after the restart and a red card for John Marquis signalled that the tide might be changing.
So Danny Cowley was pleased to see his side work hard to ultimately see the contest out with relative ease.
The Blues boss said: “It was a really good performance in the first half and credit to the players because we’ve given them an awful lot of information this week.
“They were able to digest that and implement it, which isn’t easy. But we played with a nice rhythm and were able to dominate.
“Shrewsbury changed their system after the break and we didn’t have the answers to that, so didn’t have quite the same level of control.
"We finished the game with 10, but it felt more like we had 12 players with the energy of Ryan and Marcus."
“But we’ve just come together as a group and when we’re next in that moment, we’ll be able to respond better.
“So instead we had to show the other side of the game, which is the grit, determination and resilience. We had that in abundance.
“We finished the game with 10, but it felt more like we had 12 players with the energy of Ryan and Marcus.
“If you want to be a successful team, you have to win in different ways. It would be great if we could do that by playing like we did in the first half. If you can’t then you have to dig deep.”
Cowley has suggested that Pompey will look to have Marquis’ dismissal – for a challenge on Harry Chapman – overturned.
He said: “I didn’t anticipate that the referee was going to give a red card. It’s a forward’s challenge and he actually wins the ball.
“It was probably more clumsy than anything and there was certainly no intent. I thought it was probably a yellow.
“I’ve watched it back a couple of times and seen it on slow motion and my recommendation would be to appeal.”