Kenny Jackett hailed Pompey’s dogged defending after they beat MK Dons to secure a third successive victory.
Wins at Burton and Southend – the latter in the EFL Trophy – meant confidence was high ahead of the latest Fratton contest.
And although Tom Naylor’s early header was cancelled out by Scott Fraser’s spot-kick, an Ellis Harrison penalty saw the hosts leading at the break.
But the Dons controlled possession in the second half and Jackett’s side had to produce plenty of effort to secure all three points.
The Blues boss said: “We managed to find a way to keep our noses in front and I was very pleased with the application of my players.
“From going 2-1 up, right through to the end of the game, we had to work extremely hard defensively.
“There were two big opportunities in the second half – one saw my keeper make a great save with his feet and then their keeper did the same when Ellis went through.
"We managed to find a way to keep our noses in front and I was very pleased with the application of my players."
“But they were really pushing for the equaliser and we did everything we could to hold on to our lead.
“There were shots from outside the box, but we negated any clear-cut chances, although did give away too many free-kicks and corners.
“You have to defend those set-pieces and we did that very well. It was rear-guard action and we did want to create more than we did.”
Jackett handed a league debut to Rasmus Nicolaisen straight after the interval, switching to a 3-4-3 system.
He explained: “We needed an extra centre-half in there because they were putting a lot of balls into our box.
“It’s been a good week for Rasmus, although he nearly got knocked out in his first minute – welcome to English football!
“I thought he made a good impact and we do need to be adaptable in order to stay compact, especially when you’re playing a possession-based side.”