There were 82 minutes on the clock when Gillingham finally had their first shot on target at Fratton Park.
And even then it was a tame effort from Brandon Hanlan that was comfortably dealt with by stand-in stopper Alex Bass.
So it was particularly frustrating for Tom Naylor that Pompey were unable to break their opponents down at the other end.
Gareth Evans and Ben Close were both denied by good saves, while Sean Raggett headed against the inside of the post.
And Naylor was disappointed that the Blues were unable to convert their dominance into a more positive result.
Pompey’s skipper said: “Gillingham came here with a game-plan to just sit back, but we still had plenty of chances to score.
“There were quite a few in the first half and Raggett hit the post with a header – on another day we win by three or four goals.
"Gillingham came here with a game-plan to just sit back, but we still had plenty of chances to score."
“It is hard to break down a team when they play like that and just get everyone behind the ball from the first whistle.
“We started off really positively, but did take our foot off the gas a bit in the second half in terms of the pressure we applied.
“It felt early on like we were back to how it was last season – everyone knew what they were doing and we were moving the ball well.
“But we needed to score the goal during that period when we were really on top and creating a lot of opportunities.
“I do feel that if it had gone in then it would probably have been a different story, but ultimately it didn’t come.”