Aiden O’Brien continued his impressive start to life at Pompey by finding the target at Bolton.
The forward slotted home a pass from Marcus Harness to open the scoring and leave his side on course for victory.
Ultimately, however, they were denied all three points when Kieran Sadlier converted a penalty following an alleged foul on Elias Kachunga.
It was a frustrating outcome for O’Brien, who felt that the visitors had done enough to deserve victory.
But he felt that they could still be pleased with their overall display at the University of Bolton Stadium.
O’Brien said: “They had a spell in the final 10 minutes of the game, during which we had started to tire a bit.
"It's another step in the right direction from us and the only disappointment is that we couldn’t take more of our chances."
“But they were never really able to hurt us and I felt it was a dominant performance, which is a big statement when you’re away from home.
“The penalty was all they really had and I can’t think of too many more chances that we had to deal with.
“There was nothing much to trouble us at the back and I thought that our defence were absolutely brilliant throughout.
“It's another step in the right direction from us and the only disappointment is that we couldn’t take more of our chances.
“But we can certainly be happy with the overall performance and with how we played all over the pitch.
“I enjoyed it out there and on another evening, I could have seen us scoring four goals. Unfortunately, it wasn’t to be.”