It was another positive step for Pompey with the new League One campaign now just one week away.
A 2-1 victory at Crawley included a diving header from Gareth Evans that capped a fantastic attacking move.
Tom Naylor then doubled the advantage before a fierce strike from Mason Bloomfield restored some pride for the hosts.
Kenny Jackett was happy with the overall display from his side, while believing there is still plenty of room for improvement.
The Blues boss said: “It was a bit disappointing that we couldn’t keep a clean sheet, but we competed very well.
“Our first goal was excellent, with a good ball from Naylor, the early cross from Harness and then Gareth arriving late with a great header.
“Once it went to 2-0 I thought we were slightly sloppy mentally and gave our opponents a few chances.
"Our first goal was excellent, with a good ball from Naylor, the early cross from Harness and then Gareth arriving late with a great header."
“We also need to be more ruthless with our counter-attacking football and when we get the ball in and around the box.
“But there were a lot of good opportunities created by us, while our defensive performance overall was very solid.”
All four of the substitutions made by Pompey happened in the closing stages of the Broadfield Stadium contest.
Jackett said: “I wanted to give the players who started close to 90 minutes, although there were a few changes towards the end because I wasn’t going to take any risks.
“We also looked to slow the game down a little bit and make sure that we got ourselves over that line.”
Sean Raggett missed out for the Blues after requiring stitches in his elbow following a behind-closed-doors friendly earlier in the week.