If Blackburn are one of the favourites for promotion, then Pompey can certainly be encouraged by their performance against them.
But it counted for little as Rovers snatched a late goal to make the long journey back north with three points in the bag.
Adam Armstrong took advantage of a fortunate ricochet to score after his earlier effort had been cancelled out by Conor Chaplin.
There was plenty on show to please Kenny Jackett, although he conceded that his side are missing a spark.
The Blues boss said: “Blackburn have a lot of quality in the box and in the end that was telling.
“Their second goal seemed to come off Matt Clarke’s standing leg and it just fell to Armstrong. Our keeper had no chance with either of them.
"Sometimes we’re trying to knock the door down rather than unlock it."
“We had a lot of pressure and it was a frustrating night for us because there was a lot of effort in our performance.
“There were certain aspects of our play that weren’t right, but we built up a lot of momentum and showed a great attitude.
“We have to keep working at our cohesion and quality, though, because sometimes we’re trying to knock the door down rather than unlock it.
“So we need to be a bit more clinical with our decisions, like the final pass, but I can’t fault the tempo or desire to play for Pompey.
“Both our full-backs got into decent areas and we just couldn’t find finishing to match all the balls going into the box.
“I don’t want to take away the application or passion that’s there, but there’s just that little bit that’s keeping us from being a very good team.”
It was an encouraging night for Chaplin, who added to the winning goal he scored at MK Dons on Satuday.
Jackett said: “I was pleased for Conor. He’s got two in two games now and there’s a lot for him to build on. It’s unbelievable that he’s just coming up to his 21st birthday.
“But he’s got plenty of experience and I think he’s ready to be a mainstay of the team. It certainly looked that way.”