Pompey showcased their footballing talents during a midweek League One victory at Lincoln.
But other qualities needed to come to the fore to secure three points on a bitterly cold afternoon in Gillingham.
The Kent contest appeared to be heading for a goalless draw before Michael Jacobs’ late effort was deflected into the net by defender Jack Tucker.
And Danny Cowley was delighted with the way his troops stood up to the physical challenge set by their hosts.
The Blues boss said: “It’s a fantastic outcome and probably our best win of the season against a direct and powerful Gillingham side.
“We had no natural centre-halves, so to keep a clean sheet was a magnificent effort – the winner in the final moments was well deserved.
“It’s never easy coming to Priestfield and facing a Steve Evans team. You certainly know what you’ll be up against.
“You have to compete without getting dragged into that. I don’t think we did well enough with the ball, but we found a way and sometimes the will is more important than the skill.
“The way Gillingham set up means it’s hard to get rhythm and the ball is always off the pitch, while they take long throws from everywhere.
"It’s a fantastic outcome and probably our best win of the season against a direct and powerful Gillingham side.
“But a lot of our physical, aerial players were missing, so the group deserve a lot of credit for doing what they did.
“We’ll play a lot better than that and it certainly wasn’t a game for the purists, but if you want to be a good team then you have to win all different kinds of matches.
“We came from behind to beat AFC Wimbledon last week, performed really well on Tuesday and then had to dig deep to find a goal in inujury-time against Gillingham.
“I’m really pleased for Michael and we desperately tried to find a way to fit him into the side. You can feel he’s in a really good moment.
“He didn’t sulk and understood the decision, so we’re delighted that he was able to come on and have that impact.
“You saw those celebrations at the end and our supporters are fantastic. They must have sucked that ball into the net. The result was the least they deserved.
“It’s nice to win while you’re a work in progress – and there’s a lot for us still to do. But it’s a good habit and the boys are fighting for each other.”
Cowley was surprised to receive a yellow card from referee Dean Whitestone after Pompey scored their winner.
He said: “I think it was for over-celebrating, which I wasn’t sure was possible. I wasn’t doing flips and somersaults. It was amazing that I got booked and nobody else did.”